Berkeley was born on July 1, 1907, at Quarters M-7, Marine Barracks within Navy Yard at Portsmouth, Virginia, where his father, Captain Randolph C. Berkeley, was stationed as commander of the Marine detachment aboard the battleship USS Kentucky.
His father later received the Medal of Honor during Veracruz Expedition and retired with the rank of Marine major general in the Marine Corps in 1939.

His mother, Carrie Anna Phillips, died during his birth and because of his father's occupation, James was entrusted to the care of his grandfather, who served with the Navy Pay Corps.
James rejoined his father in 1923 and after the attending of public school in Shepherdstown, West Virginia, he was sent to the Severn Preparatory school, a preparatory school for the Naval Academy.

When he failed the entrance examination to the Naval Academy, his father gave him a choice: go to work or join the Marine Corps as an enlisted man.
He chose the Marine Corps and enlisted as a private on March 1, 1927.
Private Berkeley was subsequently sent for the recruit training at Marine Corps Recruit Depot Parris Island, South Carolina.
After completing training, he was attached to the 2nd Marine Brigade under Brigadier General Logan Feland and sailed for Nicaragua in January 1928.

He took part in skirmishes with the Sandino rebels in the north of country and quickly received promotion to corporal.
Berkeley was subsequently recommended for promotion to sergeant due to his leadership skills, but his father, who served as 2nd Brigade's Chief of Staff, blocked the promotion, saying his son was too young.
James Berkeley later used this story to prove that his father's influence had not helped him in his military career.
He was decorated for bravery with the Presidential Medal of Merit by the Government of Nicaragua.

Upon his return to the United States in December 1928, he continued serving and was later promoted to sergeant.
Berkeley was also a Distinguished Marksman and received the Marine Corps Good Conduct Medal for his exemplary service.

After three years as a non-commissioned officer, he was commissioned a second lieutenant on January 31, 1930.
Berkeley was subsequently appointed company officer and ordered to the Basic School at Philadelphia Navy Yard for officers' training during the summer of that year.
He graduated in June 1931 and served for a brief period with the Marine barracks at Norfolk Navy Yard.

Second Lieutenant Berkeley was subsequently attached to the 4th Marine Regiment and left with it for China in April 1932.
He was subsequently stationed in Peiping with the Marine detachment at the American embassy and then served in the 38th Company under Captain John W. Thomason.
While in this capacity, he served as acting communications officer, the branch which significantly influenced him in his later career.

Berkeley returned stateside in December 1934 just for Christmas.
After brief leave, Berkeley was assigned to the 2nd Battalion, 6th Marines under Lieutenant Colonel Thomas E. Watson at San Diego, California.
He was appointed Battalion Communications Officer and for this new duty, he was promoted to first lieutenant in February 1935.

He was subsequently transferred to Marine Corps Base Quantico, Virginia, in May 1935 and attached to the staff of 1st Marine Brigade under Brigadier General James J. Meade.
Berkeley commanded the brigade's communications platoon until August 1936, then was sent to the Army Signal School at Fort Monmouth, New Jersey.
Following his graduation in June 1937, Berkeley rejoined the 1st Marine Brigade and was promoted to the rank of captain in September of that year.
He subsequently served as commander of the communications platoon and from April 1938 as brigade communications officer.
He left the 1st Brigade in March 1939 and assumed command of the Marine detachment aboard the heavy cruiser USS Wichita.
Berkeley spent the next two years on sea duty and took part in her shakedown cruise, during which she visited the Virgin Islands, Cuba, and the Bahamas, before she returned to Philadelphia for post-shakedown repairs.
Berkeley was born on July 1, 1907, at Quarters M-7, Marine Barracks within Navy Yard at Portsmouth, Virginia, where his father, Captain Randolph C. Berkeley, was stationed as commander of the Marine detachment aboard the battleship USS Kentucky. His father later received the Medal of Honor during Veracruz Expedition and retired with the rank of Marine major general in the Marine Corps in 1939.
His mother, Carrie Anna Phillips, died during his birth and because of his father's occupation, James was entrusted to the care of his grandfather, who served with the Navy Pay Corps. James rejoined his father in 1923 and after the attending of public school in Shepherdstown, West Virginia, he was sent to the Severn Preparatory school, a preparatory school for the Naval Academy.
When he failed the entrance examination to the Naval Academy, his father gave him a choice: go to work or join the Marine Corps as an enlisted man. He chose the Marine Corps and enlisted as a private on March 1, 1927. Private Berkeley was subsequently sent for the recruit training at Marine Corps Recruit Depot Parris Island, South Carolina. After completing training, he was attached to the 2nd Marine Brigade under Brigadier General Logan Feland and sailed for Nicaragua in January 1928.
He took part in skirmishes with the Sandino rebels in the north of country and quickly received promotion to corporal. Berkeley was subsequently recommended for promotion to sergeant due to his leadership skills, but his father, who served as 2nd Brigade's Chief of Staff, blocked the promotion, saying his son was too young. James Berkeley later used this story to prove that his father's influence had not helped him in his military career. He was decorated for bravery with the Presidential Medal of Merit by the Government of Nicaragua.
Upon his return to the United States in December 1928, he continued serving and was later promoted to sergeant. Berkeley was also a Distinguished Marksman and received the Marine Corps Good Conduct Medal for his exemplary service.
After three years as a non-commissioned officer, he was commissioned a second lieutenant on January 31, 1930. Berkeley was subsequently appointed company officer and ordered to the Basic School at Philadelphia Navy Yard for officers' training during the summer of that year. He graduated in June 1931 and served for a brief period with the Marine barracks at Norfolk Navy Yard.
Second Lieutenant Berkeley was subsequently attached to the 4th Marine Regiment and left with it for China in April 1932. He was subsequently stationed in Peiping with the Marine detachment at the American embassy and then served in the 38th Company under Captain John W. Thomason. While in this capacity, he served as acting communications officer, the branch which significantly influenced him in his later career.
Berkeley returned stateside in December 1934 just for Christmas. After brief leave, Berkeley was assigned to the 2nd Battalion, 6th Marines under Lieutenant Colonel Thomas E. Watson at San Diego, California. He was appointed Battalion Communications Officer and for this new duty, he was promoted to first lieutenant in February 1935.
He was subsequently transferred to Marine Corps Base Quantico, Virginia, in May 1935 and attached to the staff of 1st Marine Brigade under Brigadier General James J. Meade. Berkeley commanded the brigade's communications platoon until August 1936, then was sent to the Army Signal School at Fort Monmouth, New Jersey. Following his graduation in June 1937, Berkeley rejoined the 1st Marine Brigade and was promoted to the rank of captain in September of that year. He subsequently served as commander of the communications platoon and from April 1938 as brigade communications officer. He left the 1st Brigade in March 1939 and assumed command of the Marine detachment aboard the heavy cruiser USS Wichita. Berkeley spent the next two years on sea duty and took part in her shakedown cruise, during which she visited the Virgin Islands, Cuba, and the Bahamas, before she returned to Philadelphia for post-shakedown repairs. 
James P. Berkeley