Activists smoked cannabis outside the White House to send their message that the plant shouldn't be considered dangerous.
Protesters had planned to display a 51-foot (15.3-meter)-long inflatable "joint" at Saturday's demonstration. However, protest organizer Adam Eidinger said the Secret Service wouldn't allow it, citing security concerns.
Possession of up to 2 ounces (56 grams) of pot is legal in the U.S. capital, but smoking in public is illegal. However, U.S. Park Police Sgt. Anna Rose says her agency made no arrests. Eidinger said police "were very respectful."
Protest organizers say President Barack Obama should remove pot from the list of Schedule 1 controlled substances, which includes heroin and other addictive drugs. Obama has maintained that cannabis advocates should try to lobby Congress to pass a bill reclassifying the drug.