Born on November 3, 1866, in Mogadore, Ohio,[1] Purdy moved with his parents to Illinois in 1870.

[1] In his latter years in Washington, D.C., he became known as the "chief trust buster" for his work on anti-trust cases.

[3] He won the Northern Securities Co. v. United States case for the U.S.[4] Purdy received a recess appointment from President Theodore Roosevelt on July 6, 1908, to a seat on the United States District Court for the District of Minnesota vacated by Judge William Lochren.

[1] His service terminated on March 3, 1909, after his nomination was not confirmed by the United States Senate.

[3] Purdy remained in Shanghai, China, working for a finance company until 1936, when he retired.