He spent much of his childhood and youth on his family's estates in the lower Cape Fear River area, but soon became active in the colonial military structure in North Carolina.

[8] His nine aunts and uncles, and seventeen siblings and cousins on his father's side, married into other affluent families, developing a strong network in the region that perpetuated their wealth and influence,[9] and increased their slaveholdings in each successive generation.

[7] One son, James Moore Jr., would serve in the American Revolutionary War as a lieutenant before being permanently disabled by wounds received at the Battle of Eutaw Springs.

In 1758, Governor Arthur Dobbs appointed him as the captain of a provincial garrison company at Fort Johnston, and Moore remained in command of that unit during the French and Indian War.

[14] During that conflict, Moore was captain of a company he led to South Carolina to defend that colony against Cherokee attacks brought on by the Anglo-Cherokee War.

[12] In protest of the Stamp Act, in 1766 Moore led an armed mob that occupied the de facto capital town of Brunswick, North Carolina.

[20] Moore participated in the Wilmington chapter of the Sons of Liberty beginning in 1770, and through them organized a boycott of imported British goods on the Cape Fear River.

In August 1775, he was elected to the Third Provincial Congress, which organized the colonial militia and placed Moore in command of the first regiment raised to be trained as regular soldiers.

[22] His service dates were:[23] On February 15, 1776, Moore was given command of the 1st North Carolina Regiment raised at the direction of the Second Continental Congress, and placed in charge of the defense of the Cape Fear region.

This force, concentrated around the Loyalist hotbed of Cross Creek (near modern-day Fayetteville), alarmed the Patriot government, who dispatched Moore and Caswell to contain the growing army.

[26] The British Army and Royal Navy, in cooperation with the Loyalist elements of the colonial government under Governor Josiah Martin, planned an invasion of North Carolina near Wilmington, a burgeoning and strategically located seaport in the Cape Fear region.

[27] Moore led his command upriver along the south bank of the Cape Fear and fortified a river crossing at Rockfish Creek, which would have been the Loyalists' most direct path to Wilmington.

He positioned a detachment of men at Cross Creek, and ordered the regiments of Colonels Caswell and Alexander Lillington to a location downriver in the path of the Loyalist militia.

Simultaneously with Caswell's corrective maneuver, Moore floated his troops 60 miles (97 km) downriver, where they disembarked and joined in the pursuit of MacDonald's force.

[35] As a brigadier, he served under General Charles Lee, commander of the army's Southern Department, and was tasked with guarding Wilmington from attacks by British ships in the Cape Fear area after the Battle of Moore's Creek Bridge.

[17] In that capacity, Moore alternately harassed and observed British and Loyalist forces while simultaneously improving Wilmington's defenses by erecting two new coastal batteries, and by scuttling ships in the main channel of the Cape Fear River south of the city to bar passage by larger vessels.

[36] In April and May 1776, some British units from the approximately 7,000-strong force of General Sir Henry Clinton disembarked near Wilmington, and threatened to confront Moore's garrison of 1,847 men.

[38] After the near-engagement at Wilmington, Moore devised a plan by which the Provincial Congress raised five additional companies of men to defend North Carolina's coast.

Despite these efforts, the North Carolinians suffered from rampant colds and pneumonia, and many of the enlisted men deserted to join the South Carolina line because of the high bounty being offered by that state for service.

[17] Moore himself had returned to North Carolina on January 8, 1777, in an attempt to alleviate the poor conditions in which his soldiers found themselves, and to raise funds to pay his men, leaving the Southern Department under the command of Brigadier General Robert Howe.

[49] The Wake Forest, North Carolina chapter of the Daughters of the American Revolution[50] and a U.S. Army battery at the now defunct Fort Casey in Washington state[51] were named in his honor.