MEMPHIS, Tenn. -- Richard Copley's passion for taking pictures put him on the front line of this city's darkest days.
"I'm not sure I truly realized how important these images would be," he said.
In 1968, at the age of 22, he was hired to take pictures by the American Federation of state, county, and municipal employees.
"First assignment was at Mason Temple. Dr. King had come to town. It was a packed house."
Copley documented what would be Dr. Martin Luther King's last march.
"I will never forget that morning. The marchers, the families, friends and the sanitation workers themselves, all dressed nicely in their Sunday meeting clothes."
It was also on that day he took one of the most celebrated photos: I am a man.
"These gentlemen were -- are -- heroes. They are absolutely heroes."
Copley recalls how the march turned violent and Dr. King was quickly taken out of harm's way.
"All of a sudden in the background way back I heard glass breaking. It gets louder and more glass breaking, and the next thing I know all hell broke loose."
On April 3, Copley captured Dr. King during his famous I've Been to the Mountaintop speech.
"It was a night I'll never forget. The next day, I'll never forget because he was assassinated on April 4. Ironically, my father passed away on April 4th so that day is etched in my memory bank."
Four days later he was again on the front lines as Dr. King's widow led a memorial march through the streets of Memphis.
To this day, Copley considers the assignment during the sanitation worker's strike one of the most important of his career.