Born in Kosciusko, Mississippi, Niles read law to enter the bar in 1872.
He was United States Attorney for the Northern District of Mississippi from 1890 to 1891.
[1] Niles received a recess appointment from President Benjamin Harrison on August 11, 1891, to a joint seat on the United States District Court for the Northern District of Mississippi and the United States District Court for the Southern District of Mississippi vacated by Judge Robert Andrews Hill.
He was confirmed by the United States Senate on January 11, 1892, and received his commission the same day.
His service terminated on September 26, 1918, due to his death in Jackson.