Thomas Joseph Pendergast was born in St. Joseph, Missouri, in 1873. He had nine brothers and sisters. In the 1890s he worked in his brother's saloon in the West Bottoms. Here his older brother taught him about the city's political system and the advantages of controlling blocks of voters.
After his brother's death, Pendergast began to rule the democratic area. Under Pendergast, prohibition didn't keep the city from being filled with alcohol and gambling. Additionally many elections were fixed to keep political friends in power. In return, Pendergast's companies like Ready-Mixed Concrete were awarded government contracts. Under a $40 million bond program the city constructed many civic buildings during the Depression. Pendergast handpicked Harry S. Truman, the 1934 candidate for U.S. Senate.
In 1939 Pendergast was arraigned for failing to pay taxes on a bribe received to pay off gambling debts. After serving 15 months in prison, he lived quietly at his home, 5650 Ward Parkway, until his death in 1945.