After building up a reputation as a lawyer, Taft decided to run for Justice of the New York Supreme Court.

From 1905 to January 1907, he was a special assistant to Attorneys General William H. Moody and Charles Joseph Bonaparte to investigate and prosecute the Tobacco Trust.

During the trial, Taft pushed for the Tobacco Trust to release certain books, which they refused to submit as evidence.

During the annual convention of the American Bar Association, the delegates made a trip to Bohemian Grove.

The amalgamation of San Francisco Society through its love of beauty, through it cultural purpose has no duplicate in America and the Bohemian Club which unites the world of big business and the world of fine art, literature and cultural ideals could only exist in a community such as this.'

Taft was a supporter of the League of Nations, and wrote several articles on the organisation for the New York Times.

Taft was President of the Japan Society of New York from 1923 to 1929 and from 1934 to 1941, resigning in December 1941 in the wake of the attack on Pearl Harbor.