Cannon was born in North Carolina (May 7, 1836), raised in Indiana, and educated at Cincinnati Law School before settling in west-central Illinois (Danville). He was first elected to Congress in 1872 and, with the exception of two terms (1891-1892 and 1913-1915), served continuously until retiring in 1923. The total of 46 years was the longest tenure of any member of Congress before World War II. Although he authored no major piece of legislation, Cannon wielded great power as speaker of the House (1903-1910) until his ironclad rule—labeled “Cannonism”—ended when insurgent, progressive Republicans joined Democrats to vote him out of the office.

Cannon was a stand-pat conservative, but went along with most of President Theodore Roosevelt’s progressive agenda, while preventing more radical reforms. In 1904, he was considered to be a leading contender for the Republican vice-presidential nomination, but the convention selected Senator Charles Fairbanks. In 1908, Cannon was mentioned as a presidential candidate, but his chances were limited by his age (72 years old), political conservatism, and the many enemies he had made with his domineering control of the House. At the Republican National Convention, he received 58 votes while losing in a landslide to William Howard Taft.