Born on August 31, 1838, in Amherst, Ohio, Boynton read law in 1858.

He was the United States Attorney for the Southern District of Florida from 1861 to 1863.

[1] Boynton received a recess appointment from President Abraham Lincoln on October 19, 1863, to a seat on the United States District Court for the Southern District of Florida vacated by Judge William Marvin.

He was nominated to the same position by President Lincoln on January 5, 1864.

He was confirmed by the United States Senate on January 20, 1864, and received his commission the same day.