Moultrie was born in Charles Town in the Province of South Carolina.
His parents were the Scottish physician Dr. John Moultrie and Lucretia Cooper, and he was educated as a planter.

Moultrie fought in the Anglo-Cherokee War (1761).
Before the advent of the American Revolution, he was elected to the colonial assembly representing St. Helena Parish.

In 1775, Moultrie was commissioned as colonel of the 2nd South Carolina Regiment of provincial troops.
In 1776, Moultrie's defense of a small fort on Sullivan's Island (later named Fort Moultrie in his honor) prevented Sir Henry Clinton and Sir Peter Parker from taking Charleston.
The Continental Congress passed a resolution thanking Moultrie.
He was promoted to brigadier general and his regiment was taken into the Continental Army.

Moultrie successfully led a repulsive of the British at Port Royal in February 1779.
That spring when Maj.
Gen. Benjamin Lincoln took the bulk of the American force towards Augusta, Georgia, Moultrie was stationed at Black Swamp with a small contingent to watch the British on the other side of the Savannah River.
When the British suddenly crossed the Savannah en mass and tried to move on Charleston, Moultrie managed a skillful tactical retreat across the Coosawhatchie and the Tullifiny Rivers and all the way back to Charleston where he held off a short siege.
He refused to surrender at a time when the civilian authorities in Charleston felt somewhat abandoned by the Continental Congress and were almost ready to give up.

Moultrie was captured when Charleston surrendered to the British in 1780.
He was left in command of the American POWs which required all of the patience and skill of a diplomat when advocating for his men against the harsh British commandant, Lt.
Col.
Nisbet Balfour.
The British also attempted to lure him to their side, and he was absolutely indignant when he was approached by Charles Greville Montague.
Moultrie was eventually exchanged for British prisoners and in the last year of the war, he was promoted to major general in 1782, the last man appointed by Congress to that rank.

After the war he was elected by the new state legislature as 35th Governor of South Carolina (1785–87).
 The state constitution prohibited men from serving two successive terms as governor, an effort to keep power in the hands of the legislature.
Moultrie was re-elected by the legislature in 1792, serving into 1794.

In his later years, he returned to manage his plantation.
He wrote Memoirs of the Revolution as far as it Related to the States of North and South Carolina (1802).

There is evidence that William Moultrie embraced the paternal ideology that emerged during the last quarter of the eighteenth century when slave holders began to view their slaves as inferior humans rather than purely chattel.
He loathed the harsh treatment of decades past where slaves were summarily lashed for not completing a task when, as he said, "it was perhaps impossible for them to do it.”
Moultrie was born in Charles Town in the Province of South Carolina. His parents were the Scottish physician Dr. John Moultrie and Lucretia Cooper, and he was educated as a planter.
Moultrie fought in the Anglo-Cherokee War (1761). Before the advent of the American Revolution, he was elected to the colonial assembly representing St. Helena Parish.
In 1775, Moultrie was commissioned as colonel of the 2nd South Carolina Regiment of provincial troops. In 1776, Moultrie's defense of a small fort on Sullivan's Island (later named Fort Moultrie in his honor) prevented Sir Henry Clinton and Sir Peter Parker from taking Charleston. The Continental Congress passed a resolution thanking Moultrie. He was promoted to brigadier general and his regiment was taken into the Continental Army.
Moultrie successfully led a repulsive of the British at Port Royal in February 1779. That spring when Maj. Gen. Benjamin Lincoln took the bulk of the American force towards Augusta, Georgia, Moultrie was stationed at Black Swamp with a small contingent to watch the British on the other side of the Savannah River. When the British suddenly crossed the Savannah en mass and tried to move on Charleston, Moultrie managed a skillful tactical retreat across the Coosawhatchie and the Tullifiny Rivers and all the way back to Charleston where he held off a short siege. He refused to surrender at a time when the civilian authorities in Charleston felt somewhat abandoned by the Continental Congress and were almost ready to give up.
Moultrie was captured when Charleston surrendered to the British in 1780. He was left in command of the American POWs which required all of the patience and skill of a diplomat when advocating for his men against the harsh British commandant, Lt. Col. Nisbet Balfour. The British also attempted to lure him to their side, and he was absolutely indignant when he was approached by Charles Greville Montague. Moultrie was eventually exchanged for British prisoners and in the last year of the war, he was promoted to major general in 1782, the last man appointed by Congress to that rank.
After the war he was elected by the new state legislature as 35th Governor of South Carolina (1785–87).  The state constitution prohibited men from serving two successive terms as governor, an effort to keep power in the hands of the legislature. Moultrie was re-elected by the legislature in 1792, serving into 1794.
In his later years, he returned to manage his plantation. He wrote Memoirs of the Revolution as far as it Related to the States of North and South Carolina (1802).
There is evidence that William Moultrie embraced the paternal ideology that emerged during the last quarter of the eighteenth century when slave holders began to view their slaves as inferior humans rather than purely chattel. He loathed the harsh treatment of decades past where slaves were summarily lashed for not completing a task when, as he said, "it was perhaps impossible for them to do it.”
William Moultrie