Dr. Martin Luther King, Jr. was the greatest and most iconic warrior for American peaceful protest in the 20th century.
Dr. King also had armed security to protect himself and his comrades when they marched. MLK even applied for his own firearm license, but was denied by the state of Georgia.
Anybody who wants to march in the spirit of Dr. King's protests should absolutely (safely & sensibly) carry a firearm as a safety precaution.