He moved to New York City and planned the entire campaign which won the east side for the Republican Party in 1893.

In 1896 President William McKinley appointed him the collector of Internal Revenue for the Wall Street District, Elihu Root and Cornelius N. Bliss being his sponsors.

In 1905, Treat was appointed Treasurer of the United States by President Roosevelt, a post that he held until July 1909.

Funeral services were held June 2, 1910 at 3:00 p.m. at the Grace Church, New York on 802 Broadway near Tenth Street.

Charles T. Walkley, rector of the Grace Church, Orange, New Jersey, of which Treat was a communicant for fifteen years.