The apportionment of seats in this House of Representatives was based on the 1940 United States census.

The Democrats won back the majority in both chambers, and with the election of President Harry S. Truman to his own full term in office, this gave the Democrats an overall federal government trifecta.

Senators are popularly elected statewide every two years, with one-third beginning new six-year terms with each Congress.

Preceding the names in the list below are Senate class numbers, which indicate the cycle of their election, In this Congress, Class 3 meant their term ended with this Congress, requiring reelection in 1950; Class 1 meant their term began in the last Congress, requiring reelection in 1952; and Class 2 meant their term began in this Congress, requiring reelection in 1954.

The directory after the pages of terms of service lists committees of the Senate, House (Standing with Subcommittees, Select and Special) and Joint and, after that, House/Senate committee assignments.