The legislation, approved earlier this year by the D.C. Council, would continue to make public marijuana use a jailable criminal offense, but would make minor possession nothing more than a $25 civil fine -- less than the average parking ticket.
Currently, a misdemeanor marijuana possession charge can land the guilty party up to six months in jail time and a $1,000 fine.
Support for the bill grew after the ACLU issued a report last year pointing out the fact that Washington leads the nation in marijuana arrests. The study also showed that African Americans are eight times more likely to be arrested for pot possession than whites.
"This is a victory for the District and a victory for justice," said D.C. Council member Tommy Wells, who introduced the legislation. "This bill is a tremendous stride to end the disproportionate sociological and economic impact of marijuana arrests on African Americans -- arrests that pull families apart and keep our residents from jobs, higher education and housing opportunities."
Sixteen other states that have taken similar steps, but unlike most other local laws, D.C.'s legislation is subject to a 60-day review by the U.S. Congress.
Some of the more conservative Republicans in the House have hinted that they might offer some pushback.
Most Republican leaders, such as Speaker John Boehner, remained noncommittal on any official response. But a few were more vocal.
"I don't think it helps productivity in a community," Rep. James Lankford, R-Okla., told The Hill. "Decriminalizing it … I don't think that sends the right message to the next generation or the current working generation."
Even if a few politicians might offer soundbites, Congress rarely overturns the District's bills, as such an action requires the House, the Senate and the White House to be in agreement on the matter.
If Congress declines to act, the bill would go into effect this summer.