Question: William McKendree Gwin (October 9, 1805 – September 3, 1885) was an American medical doctor and politician, serving in elected office in Mississippi and California, in California he shared the distinction, along with which American explorer, politician, and soldier who, in 1856, became the first candidate of the anti-slavery Republican Party for the office of President of the United States?
Context: The 1856 United States elections elected the members of the 35th United States Congress.  The election took place during a major national debate over slavery, with the issue of "Bleeding Kansas" taking center stage.  Along with the 1854 election, this election saw the start of the Third Party System, as the Republican Party absorbed the Northern anti-slavery representatives who had been elected in 1854 under the "Opposition Party" ticket (consisting largely of former Whigs) as the second most powerful party in Congress.  Minnesota and Oregon joined the union before the next election, and elected their respective Congressional delegations to the 35th Congress. Elections for the President of Israel were held in the Knesset on 31 July 2000, following Ezer Weizman's resignation.  Moshe Katsav, a prominent Likud politician, ran against Shimon Peres, a previous Prime Minister of Israel.  In a surprising upset, the Knesset elected Katsav, by 63 to 57.  Katsav assumed office as President on 1 August 2000.  He was the first President of Israel to have been sworn in for a seven-year term, as well as the first candidate from the right-wing Likud party to be elected to the office. William W. Morrow (July 15, 1843 – July 24, 1929) was a US Representative from California from 1885–1891.  Born near Milton, Wayne County, Indiana, he moved with his parents to Adams County, Illinois in 1845, attended the common schools and received private instruction.  He moved to Santa Rosa, California, in 1859, taught school and explored mining regions.  Morrow went East in 1862 to join the Union Army and served in the National Rifles of the District of Columbia.  While in the Army of the Potomac he was appointed a special agent of the United States Treasury Department in January, 1865, and was detailed to California.  He remained there and was employed during the next four years in confidential positions under the Secretary of the Treasury.  Morrow studied law, was admitted to the bar in 1869 and commenced practice in San Francisco.  He was assistant United States Attorney for California from 1870–1874, assisted in organizing the San Francisco Bar Association in 1872 and served as its president in 1892 and 1893.  Morrow served as chairman of the Republican State central committee of California 1879–1882, attorney for the State board of harbor commissioners from 1880–1883, and also special United States attorney before the French and American Claims Commission 1881–1883, and before the Alabama Claims Commission 1882–1885.  He was a delegate to the Republican National Convention in 1884, elected as a Republican to the Forty-ninth, Fiftieth, and Fifty-first Congresses (March 4, 1885 – March 3, 1891).  Morrow was not a candidate for renomination in 1890. Jesse Kilgore Dubois (sometimes styled DuBois) (January 14, 1811 – November 22, 1876) was an American politician from Illinois.  The son of a prominent early Illinois citizen, Dubois was elected to the Illinois House of Representatives while he was attending Indiana College.  Nicknamed Uncle Jesse, he served four two-year terms there.  An early Republican, Dubois was named the party's first candidate for Auditor of Public Accounts.  He was elected in 1856 and served two four-year terms.  He was the father of Senator Fred Dubois. John Charles Frémont or Fremont (January 21, 1813July 13, 1890) was an American explorer, politician, and soldier who, in 1856, became the first candidate of the anti-slavery Republican Party for the office of President of the United States.  During the 1840s, when he led four expeditions into the American West, that era's penny press and admiring historians accorded Frémont the sobriquet "The Pathfinder". James Matthes Talent (born October 18, 1956) is an American politician and former U.S. Senator from Missouri.  He is a Republican and resided in the St. Louis area while serving in elected office.  He identifies with the conservative wing of the Republican party, being outspoken on judicial appointments, abortion, flag burning, and defense issues. Hibernian Hall is a historic meeting hall and social venue at 105 Meeting Street in Charleston, South Carolina, United States.  Built in 1840, it is Charleston's only architectural work by Thomas Ustick Walter, and a fine example of Greek Revival architecture.  It is nationally significant for its use during the 1860 Charleston Convention, in which the Democratic Party, divided by opinions on slavery, failed to select a presidential nominee, ensuring victory for the anti-slavery Republican Party in the 1860 presidential election.  The building was designated a National Historic Landmark in 1973.  The building continues to be used as a function and meeting space today. Francis K. (Frank) Koehn is a prominent activist and politician in Northern Wisconsin.  He is most notable for being the first Green Party candidate to be elected to office in the United States when he was elected Bayfield County supervisor on the Lake Superior Greens ticket in 1986.  Koehn's 12 years on the Board of Supervisors (1986–1998) is one of the longest tenures in elected office for any Green Party member, and after Dave Conley (22 years) is the second longest among Wisconsin Greens.  Koehn has also been active in environmental, treaty rights and human rights causes including opposition to the Crandon and White Pine mines, support of Ojibwe treaty rights, and support for the proposed Seventh-Generation Amendment to the US Constitution.  Koehn has paid particular efforts to preserving Lake Superior.  In many of these causes, Koehn worked closely with Walter Bresette.  He is considered a founding member of the Wisconsin Green Party and remains active in it.  Koehn was also a schoolteacher in the South Shore Schools in Port Wing, Wisconsin until recently.  He currently lives in Herbster, Wisconsin. William McKendree Gwin (October 9, 1805 – September 3, 1885) was an American medical doctor and politician, serving in elected office in Mississippi and California.  In California he shared the distinction, along with John C. Frémont, of being the state's first U.S. senators.  Before, during, and after the Civil War, Gwin was well known in California, Washington, DC, and in the south as a determined southern sympathizer. Reinhardt Voorhees Metzger (April 12, 1898- 1975) was an American Republican Party politician who served in the New Jersey General Assembly and an Independent candidate for Governor of New Jersey in 1961.  He won a Special Election for the New Jersey General Assembly in 1953 to replace William F. Tompkins, who had resigned to become U.S. Attorney for New Jersey.  He was elected to a full term in 1953 representing Essex County, but was not a candidate for re-election in 1955.  He left the Republican Party in 1961 to run as a Conservative candidate for Governor.  He received 5,820 votes (0.27%) of the vote.  He later served as President of the New Jersey Conservative Club.  In a speech to the Central New Jersey Conference of Conservatives in 1962, Metzger said: "You will have to decide which is more important, your party tag or your principles -- your party label or your freedom and principles of life and government."  Metzger urged conservatives not to vote for Republican candidates that failed to adhere to conservative principles, but instead write in the names of a better candidate.  Metzger was born in Philadelphia.  He was married to Agnes Kearney Lake (1907-1960) from 1933 until her death in 1960.
Answer: John Charles Frémont