Private Manuel Francisco Diaz was born at Ferrol, Spain ca. 1840, and was a resident of Key West, Florida since 1858.

He was mustered into service as a seaman on January 25th, 1862 with Captain Henry Mulrenan’s Florida Volunteer Coast Guards. He remained in this unit until mustered into Confederate service on April 25th, 1862 when he was enlisted as a Private in Captain Smith’s Company (Key West Avengers), 7th Regiment Florida Infantry by Major R. B. Thomas at Tampa, Florida for a period of 3 years or the war.

He was reported present on all rolls until November 3rd, 1862 when he was reported absent sick in the hospital at Knoxville, Tennessee. He was present on all subsequent muster rolls until March 3rd, 1864. On that date, he was transferred to the C.S. Navy and was assigned to the CSS Savannah as a seaman.

He served in Css Savannah until December 21st, 1864, when the vessel was fired and scuttled to avoid capture by General Sherman’s forces at Savannah. He, along with Robert Watson, was briefly sent to Charleston, South Carolina; then to Fort Fisher, near Wilmington, North Carolina. Following the fall of Fort Fisher in January 1865, they traveled by rail to Richmond, Virginia, assisting in the defense of the James River. He was captured as a member of Admiral Semmes' naval brigade near near Farmville, Virginia on April 6th, 1865.

After the war, Diaz returned to Key West and found employment as a sailor. He married Ascunsion Cabeza in Monroe County, Florida, August 24, 1888.

In 1907 was a member of Camp Franklin Buchanan No. 1214, United Confederate Veterans, of Monroe County. He was reported to be an odd job worker in 1910.

He drew a Confederate pension until his death on September 27, 1910 at at Key West, Monroe County, Florida. Asuncion applied for and was granted a Confederate Widow's Pension for her husband's service.