 He received an Artium Magister degree from Union College in 1896, and was in private practice of law in Schenectady, New York from 1895 to 1920.He served as corporation counsel for Schenectady from 1910 to 1913, in 1916, in 1917, and in 1920.

Cooper was nominated by President Woodrow Wilson on April 29, 1920, to the United States District Court for the Northern District of New York, to a new seat created by 40 Stat.1156.