James Chalmers was a Loyalist officer and pamphleteer in the American Revolution.
Born in Elgin, Moray, Scotland, Chalmers was an ambitious military strategist during the War of Independence, but was apparently kept at arm's length by British commanders Sir William Howe and Sir Henry Clinton.
In 1776 he authored a pamphlet entitled Plain Truth, a rebuke of Thomas Paine's Common Sense. Going under the pen name "Candidus", so as to not be convicted of seditious libel, Chalmers attacked Paine's views as "quackery".
After conditions grew intolerable in Chestertown, Maryland, where he lived, Chalmers accompanied the British army up the Chesapeake Bay as it made its way to Philadelphia in August 1777. After the Battle of Brandywine in September, the city fell to the British in early October. On October 14, Chalmers was commissioned lieutenant colonel of the First Battalion of Maryland Loyalists. In correspondence with British commanders, he often advocated British occupation of the Eastern Shore of Maryland but was ignored. His regiment served with little distinction. Its only military engagement was the siege of Pensacola in 1781, where the entire regiment was captured by Spanish forces. Chalmers, however, was in British-occupied New York City at the time.
After the war, Chalmers settled in England and wrote another pamphlet attacking Paine's economic policies as well as a pamphlet regarding war in Santo Domingo. He appears to have frequently socialized with other expatriate loyalists such as William Franklin, the son of Benjamin Franklin and former Royal Governor of New Jersey.
Chalmers died at his home, 12 Paradise Row, in Chelsea, London on October 4, 1806. He was buried in the chapel near the altar of Stow Maries Church, near Chelmsford, six days later. The inscription on the stone reads: "Beneath this stone are deposited the remains of Col. James Chalmers late of Chelsea, County of Middlesex, who departed this life Oct. 3, 1806, aged 72 years.".