Towner was admitted to the bar in 1877, and initially practiced law in Prescott, Iowa, in Adams County. In 1880, he was elected county superintendent of schools at Corning, Iowa, in which capacity he served until 1884. He resumed the practice of law in Corning. In 1887 he married Harriet Elizabeth Cole, at Corning. They had three children, Leta, Horace, and Constance. In 1890, he was elected as a judge of the third judicial district of Iowa. He also served as a lecturer on constitutional law at the University of Iowa from 1902 to 1911. He was also a pianist and a composer, who set to music "Iowa, Beautiful Land," once Iowa's official song.
U.S. Congress
In 1910 Towner ran successfully as a Republican to succeed retiring Democrat William Darius Jamieson representing Iowa's 8th congressional district in the U.S. House. He was re-elected five times. From 1919 to 1923, he was served as the House Republican Conference Chairman. He was the co-author of the first federal law to offer matching federal funds for social welfare or to offer grants-in-aid to states for health purposes. That law, known as the Sheppard-Towner Act or the Maternity and Infant Act, was designed to lower the United States' relatively high rates of infant mortality, and established maternal and child health services in each state. First offered in 1919, it passed in 1921. Although the program it created was chronically underfunded after passage and was allowed to expire in 1929, it paved the way for many similar state-federal social welfare programs in the New Deal era and thereafter. Towner was also the co-sponsor of the Towner-Sterling bill, which would have created a cabinet-level department of education. It failed to pass during his tenure in the House, and over fifty years would pass before its objective would be fully realized.
Governor of Puerto Rico
During his congressional tenure, Towner served as chairman of the United States House Committee on Insular Affairs, a committee with oversight responsibility over protectorates and territories. In early-1923, PresidentWarren G. Harding appointed Towner Governor of Puerto Rico, a post he held until September 29, 1929. His tenure was characterized by the construction several public works projects, such as the system of aqueducts in various sectors, the irrigation system in Isabela, the School of Tropical Medicine building in Puerta de Tierra, and the penitentiary. He also implemented a retirement law for public employees and a new tax law.
