62nd United States Congress
Senate

State (class)
Vacator
Reason for vacancy
Subsequent
Date of successor's installation
Arizona (1)
New seats
Arizona achieved statehood February 14, 1912
Henry F. Ashurst (D)
April 2, 1912
Arizona (3)
New seats
Arizona achieved statehood February 14, 1912
Marcus A. Smith (D)
April 2, 1912
New Mexico (1)
New seats
New Mexico achieved statehood January 6, 1912
Thomas B. Catron (R)
April 2, 1912
New Mexico (2)
New seats
New Mexico achieved statehood January 6, 1912
Albert B. Fall (R)
April 2, 1912
Colorado (3)
Vacant
Sen. Charles J.
Charles S. Thomas (D)
January 15, 1913
Iowa (2)
Lafayette Young (R)
Appointment expired April 11, 1911, upon successor's special election to finish term ending March 4, 1913.
William S. Kenyon (R)
April 12, 1911
Georgia (3)
Joseph M. Terrell (D)
Resigned July 14, 1911, due to health reasons. Successor was elected.
Hoke Smith (D)
November 16, 1911
Maine (2)
William P. Frye (R)
Died August 8, 1911. Successor was appointed September 23, 1911, and subsequently elected April 2, 1912.
Obadiah Gardner (D)
September 23, 1911
Tennessee (2)
Robert Love Taylor (D)
Died March 31, 1912. Successor was appointed to continue the term.
Newell Sanders (R)
April 11, 1912
Nevada (1)
George S. Nixon (R)
Died June 5, 1912. Successor was appointed to continue the term.
William A. Massey (R)
July 1, 1912
Illinois (3)
William Lorimer (R)
Senate invalidated election July 13, 1912.
Vacant until next Congress
Vacant until next Congress
Idaho (3)
Weldon B. Heyburn (R)
Died October 17, 1912. Successor was appointed to continue the term.
Kirtland I. Perky (D)
November 18, 1912
Maryland (1)
Isidor Rayner (D)
Died November 25, 1912. Successor was appointed.
William P. Jackson (R)
November 29, 1912
Arkansas (2)
Jeff Davis (D)
Died January 3, 1913. Successor was appointed to continue the term.
John N. Heiskell (D)
January 6, 1913
Texas (2)
Joseph W. Bailey (D)
Resigned January 3, 1913, due to investigations brought to light suspicious income and financial ties to the oil industry. Successor was appointed to continue the therm.
Rienzi Melville Johnston (D)
January 29, 1913
Tennessee (2)
Newell Sanders (R)
Appointment expired January 24, 1913, upon successor's special election to finish term ending March 4, 1913.
William R. Webb (D)
January 24, 1913
Nevada (1)
William A. Massey (R)
Appointment expired January 29, 1913, upon successor's special election.
Key Pittman (D)
January 29, 1913
Arkansas (2)
John N. Heiskell (D)
Appointment expired January 29, 1913, upon successor's special election to finish term ending March 4, 1913.
William M. Kavanaugh (D)
January 29, 1913
Texas (2)
Rienzi M. Johnston (D)
Appointment expired January 29, 1913, upon successor's special election to finish term ending March 4, 1913.
Morris Sheppard (D)
January 29, 1913
Idaho (3)
Kirtland I. Perky (D)
Appointment expired February 5, 1913, upon successor's special election.
James H. Brady (R)
February 6, 1913

Question: who were the United State Congress Senate between 1912 and 1913 ?
Answer: George S. Nixon (R), was the United State Congress Senate, until June 5, 1912, William A. Massey (R) from July 1, 1912, until January 29, 1913 and Key Pittman (D), from January 29, 1913.