[5] Blake was the mayor of Washington when British troops laid siege to the city on August 24, 1814, as part of the War of 1812.

Resolutions to place the capital in a defensive state were voted down, largely through the influence of the Secretary of War, General [John] Armstrong.

No system of alarms and outposts was established to warn the city of impending danger, and no steps were taken to use the natural advantages of an easily defended eastern boundary.

"[7] Once the army forces in Washington had surrendered, and most of the city's residents fled, Blake made a desperate last effort to hold off the British, distributing flyers and handbills and placing an ad in the evening newspaper The Daily National Intelligencer, urging "all able-bodied Citizens remaining here" to meet at the steps of the U.S. Capitol and then proceed to an arsenal at Bladensburg, Maryland, to arm themselves and defend the city.

[8] It was too late, however, to save the capital from being burned, and Blake himself finally fled across the Potomac River on the night of the 24th when it became evident that his only alternative was to be taken prisoner.

During the 1820s, Blake was a member of the prestigious society, Columbian Institute for the Promotion of Arts and Sciences, who counted among their members former presidents Andrew Jackson and John Quincy Adams and many prominent men of the day, including well-known representatives of the military, government service, medical and other professions.

His remains were interred in the Methodist Episcopal Burial Ground in Georgetown and then moved to the William A. Gordon lot in Oak Hill Cemetery in Washington, D.C., on November 2, 1870.

[11][citation needed] In 1887, the Blake Public School on North Capital Street NW between K and L, named in his honor, opened.