Martyrs' Day: Several Panamanian youths try to raise the Panamanian flag in the U.S.-controlled Panama Canal Zone, leading to fighting between U.S. military and Panamanian civilians.

Martyrs' Day is a Panamanian day of national mourning which commemorates the January 9, 1964 anti-American riots over sovereignty of the Panama Canal Zone. The riot started after a Panamanian flag was torn and students were killed during a conflict with Canal Zone Police officers and Canal Zone residents. It is also known as the Flag Incident or Flag Protests.

Panama, officially the Republic of Panama, is a country located at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and the Pacific Ocean to the south. Its capital and largest city is Panama City, whose metropolitan area is home to nearly half of the country's over 4 million inhabitants.

The Panama Canal Zone, also known as just the Canal Zone, was a concession of the United States located in the Isthmus of Panama that existed from 1903 to 1979. It consisted of the Panama Canal and an area generally extending five miles (8 km) on each side of the centerline, but excluding Panama City and Colón. Its capital was Balboa.