The apportionment of seats in the House of Representatives was based on the 1910 United States census.

Both the House and Senate remained under Republican control, with increased majorities in each chamber.

And with Herbert Hoover being sworn in as president on March 4, 1929, the Republicans maintained an overall federal government trifecta.

The count below identifies party affiliations at the beginning of the first session of this Congress, and includes members from vacancies and newly admitted states, when they were first seated.

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