[1] While working on his father's farm, Preston attended the Roxbury Academy and the Delaware Literary Institute in Franklin.
In 1889, he unsuccessfully ran for County Judge as a Democrat, losing the election to Alphonso T. Clearwater.
In 1890, Governor Hill appointed him Superintendent of the New York State Banking Department, a position he held for two terms.
At the end of his term of Superintendent, he became president of the Equitable Securities Company in New York City, a liquidated institution he helped revive.
He was also president of the National Bank Rondout from 1897 to 1902, and a receiver of the New York Building Loan-Banking Company until he left for health reasons in 1908.