Gray was born on May 4, 1840, in
New Castle,
New Castle County, Delaware, the son of
Andrew C. Gray (1804–1885), a lawyer, banker, businessman, and public official in the U.S. state of
Delaware. The younger Gray attended the common schools, received an
Artium Baccalaureus degree in 1859 from the College of New Jersey (now
Princeton University), an
Artium Magister degree in 1863 from the same institution, attended
Harvard Law School, then
read law with his father and was admitted to the bar in 1863. He entered private practice in New Castle from 1863 to 1879. He was the
Attorney General of Delaware from 1879 to 1885. Gray was a member of the
Permanent Court of Arbitration at
The Hague from 1900 to 1925. ==Congressional service==