James M. Hawes was born January 7, 1824 in Lexington, Kentucky, the son of Richard and Hettie Nicholas Hawes. The Hawes family was politically prominent. Hawes' father Richard Hawes, uncle Albert Gallatin Hawes, great-uncle Aylett Hawes, and cousin Aylett Hawes Buckner all served in the United States House of Representatives. James Hawes did not follow the family tradition, however, and enrolled at the United States Military Academy on July 1, 1841. He graduated four years later with the rank of second lieutenant of dragoons.
Upon graduation, Hawes was assigned to assist with the occupation of Texas. When war broke out with Mexico, Hawes participated in the Siege of Veracruz, and the battles of Contreras, Churubusco, and Molino del Rey. His outstanding service earned him a brevet to the rank of first lieutenant.
Following his service in the U.S.-Mexican War, Hawes became an assistant instructor at the U.S. Military Academy. Among the subjects he taught were infantry tactics, cavalry tactics, and mathematics. In 1850, he studied advanced tactics at the Cavalry School of Saumur, France. On his return to the United States in 1852, Hawes was stationed on the Texas frontier, served in the Utah expedition in 1857 and 1858, and helped put down disturbances in "Bleeding Kansas."
On February 3, 1857, Hawes married Maria Southgate at Christ Church in Cincinnati, Ohio. The couple had 10 children.
With the outbreak of the Civil War in 1861, Hawes resigned his position in the U.S. Army to accept a commission as a captain in the 2nd Kentucky Cavalry. On June 16, 1861, Hawes was promoted to the rank of major, and ten days later was promoted to colonel. He later resigned this position to be commissioned a major in the regular Confederate Army. On March 5, 1862, Hawes was promoted to brigadier general at the request of Albert Sidney Johnston. He became the cavalry commander of the Confederate Western Department.
Following the Battle of Shiloh, Hawes asked to be relieved of command and was assigned to a brigade under John C. Breckinridge. Kentucky's Confederate governor George W. Johnson was killed at the Battle of Shiloh, and the shadow government's legislative council chose Hawes' father Richard to succeed Johnson.
Records show that Hawes participated in a charge on Charleston, West Virginia, on July 4, 1861 and helped defend a bridge on the Green River near Bowling Green on September 18, 1861. He was dispatched to Little Rock, Arkansas in October 1862 to serve as head of the cavalry brigade under Theophilus H. Holmes. Later, he participated in the Battle of Sabine Cross Roads in April 1864, served in the earlier engagements at the Battle of Milliken's Bend and the Battle of Young's Point in June 1863 in Louisiana and then in Mobile, Alabama, aided the defense of Vicksburg, Mississippi, and finished his Confederate military service in Galveston, Texas.
Following the Civil War, Hawes and his wife returned to their destroyed home in Paris, Kentucky. They relocated to Covington, Kentucky in 1866, where Hawes became a hardware merchant. He still resisted the family tradition of a political career, possibly because of improprieties committed by his brother, Smith Hawes, while he was city treasurer.
Later in life, Hawes became known for decorating Confederate graves on Confederate Memorial Day. Hawes died at his home on November 22, 1889. His cause of death was listed as age and cerebritis. In January 1925, the United Daughters of the Confederacy honored Hawes with a service cross medal, which his grandson accepted on his behalf. He was buried in Highland Cemetery Fort Mitchell, Kenton County, Kentucky.