A native of Ballston, New York, Thacher was raised in Albany and educated primarily by private tutors.

A supporter of hard money during the 1890s debate over U.S. monetary policy, in 1896, he won the Democratic nomination for governor of New York.

As a collector of historical memorabilia, he acquired numerous autographs of prominent figures, including every signer of the United States Declaration of Independence.

[4] Thacher was a member of the Kappa Alpha Society, and Williams later awarded him his Master of Arts degree "as in course.

[6] As part of his work as a historian, Thacher amassed a library of Masonic literature, which he donated to Albany's Masters Lodge No.

[8] Thacher was active in politics as a Democrat and served as a member of Albany's board of health.

[3] He also secured social reforms including regulations for tenements, and an 1885 statewide census that enabled reapportionment of state legislative districts.

[3] During his first term, Thacher presided over extensive ceremonies to celebrate the bicentennial of Albany's 1686 chartering as a city.

[9] In February 1888, he organized and presided over a three day long winter carnival, the first celebration of its type south of Montreal.

[9] During his second term, Thacher oversaw the start of several construction projects, most notably Union Station at the corner of Broadway and Steuben Street.

[6] The kidnapped boy was recovered by searchers several days later, and the three kidnappers were each sentenced to fourteen years in prison.