Martin Adlai Brennan was a U.S. Representative

United States House of Representatives

The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...

 from Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

.

Born in Bloomington, McLean County, Illinois, Brennan attended parochial schools.
He was employed as a reporter for the Bloomington Bulletin.
He was graduated from the Wesleyan College of Law, Bloomington, Illinois

Bloomington, Illinois

Bloomington is a city in McLean County, Illinois, United States and the county seat. It is adjacent to Normal, Illinois, and is the more populous of the two principal municipalities of the Bloomington-Normal metropolitan area...

, in 1902.
He was admitted to the bar

Admission to the bar in the United States

In the United States, admission to the bar is the granting of permission by a particular court system to a lawyer to practice law in that system. Each U.S. state and similar jurisdiction has its own court system and sets its own rules for bar admission , which can lead to different admission...

 the same year and commenced practice in Bloomington, Illinois

Bloomington, Illinois

Bloomington is a city in McLean County, Illinois, United States and the county seat. It is adjacent to Normal, Illinois, and is the more populous of the two principal municipalities of the Bloomington-Normal metropolitan area...

.
He served as presiding judge of the Illinois Court of Claims 1913-1917.
He served as census supervisor for McLean County, Illinois, in 1920.
He served as member of the State house of representatives 1921-1923.
He served as delegate to the Democratic National Convention in 1924.

Brennan was elected as a Democrat

Democratic Party (United States)

The Democratic Party is one of two major contemporary political parties in the United States, along with the Republican Party. The party's socially liberal and progressive platform is largely considered center-left in the U.S. political spectrum. The party has the lengthiest record of continuous...

 to the Seventy-third

73rd United States Congress

The Seventy-third United States Congress was a meeting of the legislative branch of the United States federal government, composed of the United States Senate and the United States House of Representatives. It met in Washington, DC from March 4, 1933 to January 3, 1935, during the first two years...

 and Seventy-fourth

74th United States Congress

-House:Also 2 Delegates, 3 Resident Commissioners-Senate:*President of the Senate: John N. Garner *President pro tempore: Key Pittman -Majority leadership:*Majority leader: Joseph T. Robinson...

 Congresses (March 4, 1933-January 3, 1937).
He was not a candidate for renomination in 1936.
He resumed the practice of law in Bloomington, Illinois

Bloomington, Illinois

Bloomington is a city in McLean County, Illinois, United States and the county seat. It is adjacent to Normal, Illinois, and is the more populous of the two principal municipalities of the Bloomington-Normal metropolitan area...

, until his death there on July 4, 1941.
He was interred in St. Mary's Cemetery.