90th Congress (1967 - 1969)

House of Representatives

House Majority: Democrat

House Majority Seats: 248 out of 435

House Speaker: Rep. John W. McCormack (D-MA)

Senate

Senate Majority: Democrat

Senate Majority Seats: 64 out of 100

Senate Majority Leader: Sen. Mike Mansfield (D-MT)

Executive

President: Lyndon B. Johnson (D-TX)

Vice President: Hubert Humphrey (D-MN)

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Member Spotlight

Featured: Sen. Michael Joseph 'Mike' Mansfield (D-MT), the Senate Majority Leader, was a defining voice of mid-20th century American governance. Born in 1903, he served first in the House and then in the Senate, becoming Majority Leader in 1961 after Lyndon Johnson left the chamber. Mansfield led for 16 years—a record at the time—guiding the Senate through landmark legislation such as the Civil Rights Act of 1964. Known for his quiet, consensus-building style, he emphasized respect for individual senators and worked to modernize Senate procedures while reinforcing the institution’s dignity.

Enactments