Dictionary of National Biography, 1885-1900/Mercer, Hugh
MERCER, HUGH (1726?–1777), American brigadier-general, is described by American biographers as a native of Aberdeen, Scotland, born about 1721, who studied medicine at Aberdeen University. The name ‘Hugo Mercer’ is among the fourth-year students of 1744 in the ‘Album Studiensis’ of Marischal College, Aberdeen. His age, probably, was between sixteen and eighteen. The academic records afford no other particulars. Mercer was a surgeon's mate in the Pretender's army, and afterwards went to America in 1747, and settled as a doctor near what is now Mercersburg, Pennsylvania. He is said to have served in the expedition against Fort Du Quesne, under General Edward Braddock [q. v.], and to have been wounded at the Monaghahela 9 July 1756, for which he received a medal from the corporation of Philadelphia. Winthrop Sargent, in his monograph of the expedition, implies uncertainty on this point. Among the provincial officers engaged were two other Mercers, George and John, who were thanked by the burgesses (see Trans. Hist. Soc. of Philadelphia, v. 240, 329). Mercer became a lieutenant-colonel of provincials in 1758, and accompanied the expedition under Brigadier-general John Forbes against the new Fort Du Quesne, where he was for several months in command (see Parkman, Montcalm and Wolfe, xi. 49, 130–162). Mercer then returned to medical practice, establishing himself at Fredericksburg, Virginia. He organised and drilled the Virginia militia; commanded the minute men at the outbreak of the revolution; was appointed colonel of the 3rd Virginia regiment; and in June 1776, at the desire of Washington, was chosen by congress a brigadier-general, with command of a flying brigade. He accompanied Washington in his retreat through New Jersey. He led the attack on the Hessians at Trenton, and advised the night march on Princeton, in which he led the advance. His horse was disabled while he was attempting to rally his troops, mostly raw militia, and he was himself knocked down with the butt of a musket and bayoneted when on the ground. After several days of severe suffering he died of his wounds 12 Jan. 1777. His funeral was attended by 20,000 people. The St. Andrew Society of Philadelphia raised a monument to him in the Laurel Hill cemetery, and in 1790 congress made provision for the education of his youngest son, Hugh. Mercer County, Kentucky, is named after him.
Mercer had an elder son, John, who died a colonel in the United States army in 1817. The younger, Hugh, died at Fredericksburg, Virginia, in 1853, aged 77. A married daughter, Anna Gordon Patton, died in 1832, aged 58.