Senate
United States elections · 1866 · held
State Senate races in this midterm cycle, with separate candidate results and election-era ideology attribution.
State races and results map
Each race has its own denominator. Missing counts are blank. The interactive map uses modern state outlines as navigation references.
California — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Cornelius Cole | Republican | — | — | Elected |
Incumbent retired. New senator elected in 1866 or 1867. Republican gain. Source candidate / selection detail: ▌Y Cornelius Cole (Republican)
[data missing]
Sources & further reading
Connecticut — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Orris S. Ferry | Republican | — | — | Elected |
| Lafayette S. Foster | Republican | — | — | — |
Incumbent lost re-election. New senator elected in 1866. Republican hold. Source candidate / selection detail: ▌Y Orris S. Ferry (Republican)
▌Lafayette S. Foster (Republican)
[data missing]
Sources & further reading
Georgia — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Joshua Hill | Republican | — | — | Elected |
New senator elected in 1867. Senate refused to seat the winner. Seat remained vacant until 1871 when Georgia was readmitted. Source candidate / selection detail: ▌Y Joshua Hill (Republican)
[data missing]
Sources & further reading
Illinois — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Lyman Trumbull | Republican | — | — | Elected |
Incumbent re-elected in 1867. Source candidate / selection detail: ▌Y Lyman Trumbull (Republican)
[data missing]
Sources & further reading
Indiana — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Oliver P. Morton | Republican | — | — | Elected |
Incumbent retired or lost re-election. New senator elected in 1867. Republican hold. Source candidate / selection detail: ▌Y Oliver P. Morton (Republican)
[data missing]
Sources & further reading
Iowa — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| James Harlan | Republican | — | — | Elected |
| Henry Hoffman Trimble | Democratic | — | — | — |
Incumbent lost nomination. New senator elected January 13, 1866. Republican hold. Source candidate / selection detail: ▌Y James Harlan (Republican) 118 votes
▌Henry Hoffman Trimble (Democratic) 20 votes
Sources & further reading
Iowa — Senate (Class 3) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Samuel J. Kirkwood | Republican | — | — | Elected |
Incumbent resigned May 15, 1865, to become U.S. Secretary of the Interior. New senator elected January 13, 1866. Republican hold. Winner did not run for re-election to the next term; see below. Source candidate / selection detail: ▌Y Samuel J. Kirkwood (Republican)
[data missing]
Sources & further reading
Kansas — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Samuel C. Pomeroy | Republican | — | — | Elected |
Incumbent re-elected in 1867. Source candidate / selection detail: ▌Y Samuel C. Pomeroy (Republican)
[data missing]
Sources & further reading
Kansas — Senate (Class 2) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Edmund G. Ross | Republican | — | — | Elected |
Interim appointee elected January 23, 1867 to finish the term. Source candidate / selection detail: ▌Y Edmund G. Ross (Republican)
[data missing]
Sources & further reading
Kentucky — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Garrett Davis | Democratic | — | — | Elected |
| Benjamin Bristow | Unconditional Union | — | — | — |
| Lazarus Powell | Democratic | — | — | — |
| John C. Breckinridge | Democratic | — | — | — |
| Jesse D. Bright | Democratic | — | — | — |
| William O. Butler | Democratic | — | — | — |
| James Fisher Robinson | Democratic | — | — | — |
Incumbent re-elected January 30, 1867, as a Democrat. Democratic gain. Source candidate / selection detail: ▌Y Garrett Davis (Democratic) 78
▌ Benjamin Bristow (Unconditional Union) 41
▌ Lazarus Powell (Democratic) 2
▌ John C. Breckinridge (Democratic) 1
▌ Jesse D. Bright (Democratic) 1
▌ William O. Butler (Democratic) 1
▌ James Fisher Robinson (Democratic) 1
Sources & further reading
Maine — Senate (Class 2) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Nathan A. Farwell | Republican | — | — | Elected |
Interim appointee elected January 11, 1865 to finish the term. Winner did not run for re-election to the next term; see below. Source candidate / selection detail: ▌Y Nathan A. Farwell (Republican)
[data missing]
Sources & further reading
Maryland — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Philip Francis Thomas | Democratic | — | — | Elected |
Incumbent retired or lost re-election. New senator elected in 1866 or in 1867. Senate refused to seat him, as he had "given aid and comfort" to the Confederate cause. Seat remained vacant until 1868. Unconditional Unionist loss. Source candidate / selection detail: ▌Y Philip Francis Thomas (Democratic)
[data missing]
Sources & further reading
Missouri — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Charles D. Drake | Republican | — | — | Elected |
Incumbent retired due to ill health. New senator elected in 1866 or 1867. Republican hold. Source candidate / selection detail: ▌Y Charles D. Drake (Republican)
[data missing]
Sources & further reading
Nebraska — Senate (Class 1) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Thomas Tipton | Republican | — | — | Elected |
Nebraska admitted to the Union March 1, 1867. Senator elected March 1, 1867. Republican gain. Source candidate / selection detail: ▌Y Thomas Tipton (Republican)
[data missing]
Sources & further reading
Nebraska — Senate (Class 2) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| John M. Thayer | Republican | — | — | Elected |
Nebraska admitted to the Union March 1, 1867. Senator elected March 1, 1867. Republican gain. Source candidate / selection detail: ▌Y John M. Thayer (Republican)
[data missing]
Sources & further reading
Nevada — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| James W. Nye | Republican | — | — | Elected |
Incumbent re-elected in 1867. Source candidate / selection detail: ▌Y James W. Nye (Republican)
[data missing]
Sources & further reading
New Hampshire — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| James W. Patterson | Republican | — | — | Elected |
Incumbent retired. New senator elected in 1866 or 1867. Republican hold. Source candidate / selection detail: ▌Y James W. Patterson (Republican)
[data missing]
Sources & further reading
New Jersey — Senate (Class 2) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Alexander G. Cattell | Republican | — | — | Elected |
Incumbent's election disputed and seat declared vacant. New senator elected September 19, 1866. Republican gain. Source candidate / selection detail: ▌Y Alexander G. Cattell (Republican) 44
against - none
Sources & further reading
New Jersey — Senate (Class 1) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Frederick T. Frelinghuysen | Republican | — | — | Elected |
Interim appointee elected January 23, 1867 to finish the term. Source candidate / selection detail: ▌Y Frederick T. Frelinghuysen (Republican)
[data missing]
Sources & further reading
New York — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Roscoe Conkling | Republican | — | — | Elected |
| Henry C. Murphy | Democratic | — | — | — |
| George F. Comstock | Democratic | — | — | — |
Incumbent lost renomination. New senator elected January 15, 1867. Republican hold. Source candidate / selection detail: ▌Y Roscoe Conkling (Republican)
▌Henry C. Murphy (Democratic)
▌George F. Comstock (Democratic)
Sources & further reading
Ohio — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| John Sherman | Republican | — | — | Elected |
Incumbent re-elected in 1866. Source candidate / selection detail: ▌Y John Sherman (Republican)
[data missing]
Sources & further reading
Oregon — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Henry W. Corbett | Republican | — | — | Elected |
Incumbent lost re-election. New senator elected in 1866 or 1867. Republican gain. Source candidate / selection detail: ▌Y Henry W. Corbett (Republican)
[data missing]
Sources & further reading
Pennsylvania — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Simon Cameron | Republican | — | — | Elected |
| Edgar Cowan | Republican | — | — | — |
Incumbent lost re-election. New senator elected January 15, 1867. Republican hold. Source candidate / selection detail: ▌Y Simon Cameron (Republican) 61.65%
▌Edgar Cowan (Republican) 36.84%
Sources & further reading
Tennessee — Senate (Class 1) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| David T. Patterson | Democratic | — | — | Elected |
State re-admitted to the Union. New senator elected July 24, 1866. Democratic gain. Source candidate / selection detail: ▌Y David T. Patterson (Democratic)
[data missing]
Sources & further reading
Tennessee — Senate (Class 2) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Joseph S. Fowler | Unionist | — | — | Elected |
State re-admitted to the Union. New senator elected July 24, 1866. Unionist gain. Source candidate / selection detail: ▌Y Joseph S. Fowler (Unionist)
[data missing]
Sources & further reading
Tennessee — Senate · special — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| William G. Brownlow | Republican | — | — | Elected |
| William B. Stokes | Republican | — | — | — |
Incumbent retired. Winner elected early on October 22, 1867, for the term beginning March 4, 1869. Republican gain. Source candidate / selection detail: ▌Y William G. Brownlow (Republican) 63
▌William B. Stokes (Republican) 39
Sources & further reading
Vermont — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Justin S. Morrill | Republican | — | — | Elected |
| Luke P. Poland | Republican | — | — | — |
Incumbent lost re-election. New senator elected in 1866. Republican hold. Source candidate / selection detail: ▌Y Justin S. Morrill (Republican)
▌Luke P. Poland (Republican)
[data missing]
Sources & further reading
Vermont — Senate (Class 1) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| George F. Edmunds | Republican | — | — | Elected |
Interim appointee elected October 24, 1866 to finish the term. Source candidate / selection detail: ▌Y George F. Edmunds (Republican)
[data missing]
Sources & further reading
Vermont — Senate (Class 3) — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Luke P. Poland | Republican | — | — | Elected |
Interim appointee elected October 24, 1866 to finish the term. Winner lost re-election to the next term; see below. Source candidate / selection detail: ▌Y Luke P. Poland (Republican)
[data missing]
Sources & further reading
Wisconsin — Senate — General
Legislative / indirect selection. Legislative selection; popular-vote totals are not inferred
| Candidate | Party | Votes | Share | Result |
|---|---|---|---|---|
| Timothy O. Howe | Republican | — | — | Elected |
| Charles A. Eldredge | Democratic | — | — | — |
| Edward S. Bragg | Democratic | — | — | — |
| Joshua J. Guppey | Democratic | — | — | — |
Incumbent re-elected January 23, 1867. Source candidate / selection detail: ▌Y Timothy O. Howe (Republican) 74.22%
▌Charles A. Eldredge (Democratic) 24.22%
▌Edward S. Bragg (Democratic) 0.78%
▌Joshua J. Guppey (Democratic) 0.78%
Sources & further reading
Results: final · partial coverage · Elected candidates in regular races; continuing senators are not included
| Party / candidate | Votes | Vote share | Seats | Electoral votes |
|---|---|---|---|---|
| Cornelius Cole · California | — | — | 1 | — |
| Orris S. Ferry · Connecticut | — | — | 1 | — |
| Joshua Hill · Georgia | — | — | 1 | — |
| Lyman Trumbull · Illinois | — | — | 1 | — |
| Oliver P. Morton · Indiana | — | — | 1 | — |
| James Harlan · Iowa | — | — | 1 | — |
| Samuel C. Pomeroy · Kansas | — | — | 1 | — |
| Garrett Davis · Kentucky | — | — | 1 | — |
| Philip Francis Thomas · Maryland | — | — | 1 | — |
| Charles D. Drake · Missouri | — | — | 1 | — |
| James W. Nye · Nevada | — | — | 1 | — |
| James W. Patterson · New Hampshire | — | — | 1 | — |
| Roscoe Conkling · New York | — | — | 1 | — |
| John Sherman · Ohio | — | — | 1 | — |
| Henry W. Corbett · Oregon | — | — | 1 | — |
| Simon Cameron · Pennsylvania | — | — | 1 | — |
| Justin S. Morrill · Vermont | — | — | 1 | — |
| Timothy O. Howe · Wisconsin | — | — | 1 | — |
The seat diagram shows only regular seats contested in this cycle, not the full Senate. Special races remain available in the state selector. Early cycles span two years and use legislative selection; missing or non-comparable vote totals are left blank. Candidate ideology is used where sourced; otherwise the broad election-era party tradition is used. Unassessed candidates are not assigned an ideology.
Sources & further reading
U.S. Senate historical party divisions