Medical marijuana users took their complaints to Congress on Monday.
Concluding a three-day conference in Washington, the group Americans for Safe Access organized 200 medical marijuana advocates from 37 states for its second annual lobbying day on Capitol Hill, lining up more than 300 meetings with legislative offices.
Pot backers say Congress needs to get involved to resolve a growing conflict between state and federal laws.
In January, President Barack Obama said reclassifying marijuana and making it legal in any way "is a job for Congress."
In February, 18 members of the U.S. House of Representatives told Mr. Obama in a letter he should use his executive power to make the change.