At the outbreak of the War of 1812, Lingan was an outspoken advocate of freedom of the press and was murdered by a mob while defending the offices of an anti-war newspaper in Baltimore.

Approached by distant cousin Samuel Hood and offered £10,000 and a commission in the British Army if he agreed to switch sides in the conflict, Lingan was reported to have replied "I'll rot first".

On one occasion, Lingan defended the body of a recently deceased prisoner from guards who wanted to behead the corpse to make it fit into a small coffin.

[1] Following his release at the end of the war, Lingan was made Collector of the Port of Georgetown by George Washington personally and became a Brigadier-General in the Maryland State Militia.

On July 17, 1812, Hanson resumed printing the newspaper at new offices in Baltimore and another mob formed within hours, again storming the building and destroying the presses.