Provost was born on April 2, 1834, in New York City, the son of David Provost, who served as justice of the peace for over 20 years, and Elizabeth Hendrickson.
[2] He then studied law under Cram & Cornell of New York City from 1852 to 1855.
He was admitted to the bar in 1855 and became the senior partner of the law firm Provost, Fisher & Daily in Williamsburg.
[4] He was a member of the Brooklyn Board of Education from 1864 to 1868, a justice of the peace and police justice in Queens County from 1870 to 1878, school commissioner of Queens County from 1874 to 1878, and president of the board of education of the fifth district of Flushing for five years.
He served in the Consistory of the First Reformed Church of Brooklyn.