Lachlan McIntosh, born near Inverness, Scotland, on the 17th of March, 1727, emigrated with his family to America in 1736 and settled in Georgia. His early education was but limited, and at the age of seventeen, being thrown upon his own resources by the death of his father, he removed to Charleston, South Carolina, and entered a counting-house as clerk. After several years, however, he adopted the calling of land surveyor, married, and returned to Georgia, employing his spare time in the study of civil engineering and military tactics. Having gained the confidence and esteem of his fellow-citizens, when hostilities began with Great Britain he was made colonel-commander of the Georgia troops, and on the 16th of September, 1776, promoted by Congress to be brigadier-general. In 1777, he was employed for a considerable time in watching the motions of General Howe in Philadelphia. In 1778, he headed an expedition against the Indian tribes along the Ohio, and succeeded in giving repose to all western Pennsylvania and Virginia. In 1779, he joined General Lincoln in the invasion of Georgia, which proving unsuccessful, the Americans retreated to Charleston, South Carolina, where they were besieged and obliged to surrender on the 12th of May, 1780.

General McIntosh was held a prisoner for a long period, and when he was released, the war was practically over. On the 30th of September, 1783, he became major-general by brevet, and retired to his home in Georgia. In 1784, he served as member of Congress, and the next year as a commissioner to treat with the Southern Indians. The war, however, depreciated the value of his real estate, so that his latter years were passed in comparative poverty and retirement. He died in Savannah on the 20th of February, 1806, in the seventy-ninth year of his age.