He wanted to be a member of the Supreme Court, but due to his wife's urging and with the support of his friend Theodore Roosevelt became president. Taft made his climb in politics starting at the bottom and through diligence progressed rapidly. Under McKinley he was appointed chief civil administrator to the Philippines in 1900 and was sympathetic to their cause. Taft helped the economy by building schools and roads, and also allowed the people to participate in government. He was a lawyer who was elected as secretary of war and as attorney general under Ulysses S. Grant along with being an ambassador to Austria and Russia. He was the heaviest of any president weighing more than 300 pounds. Between the years of 1904 and 1908 he was in charge of the construction of the Panama Canal.

Taft was also responsible for better Japanese-American relations that were worsened by the treatment of Japanese immigrants in California. His term saw the birth of the postal savings system and the parcel post, and also the creation of a separate Department of Labor. Taft continued to expand the United States foreign trade in South and Central America. He ran for a second term, but was defeated by Woodrow Wilson. After he retired from office he took pleasure in being a Kent professor of law at Yale University. Taft also served as a joint chairman of the National War Labor Board during World War I. President Harding made him Chief Justice of the United States, a position he held until just before his death in 1930. He was the only man in American history to become president and Chief Justice. A continuing heart disease forced Taft to retire from the court on February 3, 1930.