The Constitution of the Republic of Texas provided for a two-house Congress. The House of Representatives was to be made up of "not less than twenty-four nor more than forty members," until such time as the population of the republic should exceed 100,000. When the population exceeded this number the house was to be made up of "not less than forty nor more than one hundred members provided that each county was entitled to at least one representative." Members of the House served one-year terms. A member had to be twenty-five or older, a citizen of the republic, and a resident of his district for six months. The House chose its speaker and had sole power of impeachment. The Senate was to have a membership numbering "not less than one-third nor more than one-half that of the House." The Senate was also chosen by districts that were as nearly equal as possible to the population of free men. Each district was entitled to no more than one member. A senator had to be thirty or older, a citizen of the republic, and a resident of his district for one year. Senators served three-year overlapping terms, with one-third of the members being elected each year. The Senate chose its own officers and president pro tem and had sole responsibility to try impeachments. Each house was to judge election and qualification of its own members. A quorum in either house was two-thirds of its membership. Members were to receive pay as fixed by law, but no change could be made in salary in the session in which the change was made.
The first Congress, which convened at Columbia on October 3, 1836, was made up of thirty representatives and fourteen senators. Lorenzo de Zavala, as vice president, was president of the Senate until October 22, when Mirabeau B. Lamar was inaugurated. Ira Ingram was elected speaker of the House, and Richard Ellis was elected president pro tem of the Senate. Since members of the House were elected for one-year terms, each Congress lasted only one year. In its short history, the Republic of Texas had nine congresses.