A man was hanged for tearing down a US flag during the American Civil War.

On April 26th 1862 in New Orleans, Captain Henry W. Morris sent ashore Marines from the USS Pocahontas to raise the US flag over the confederate one. As they tried to raise the flag, a group of 7 angry, local individuals, including William Bruce Mumford decided to remove the flag from the mint. 

The Pocahontas fired and Mumford was injured by a flying brick, but he still managed to take the flag to the mayor at city hall.  By the time he got there, it had been torn to pieces by onlookers.

Mumford was arrested and charged with "high crimes and misdemeanors against the laws of the United States." He was hanged in the courtyard of the mint itself. 

Before the execution however, he was allowed to give one final speech, in which he talked to the multitude that had assembled about patriotism for the Confederacy and his love for the true meaning of the American flag. 

(Source)