Making history, President Joe Biden took the unprecedented step of issuing pardons for all Americans convicted of simple marijuana possession charges under federal law, according to Politico. He is now stressing to governors nationwide the importance of taking similar action.

The move also fulfills Biden’s campaign promise to expunge previous federal possession convictions and start the effort to make changes to the federal classification of marijuana, according to CNN. Biden’s announcement comes just one month ahead of the midterm elections, which are particularly significant because they will decide which party controls Congress.

“Sending people to prison for possessing marijuana has upended too many lives and incarcerated people for conduct that many states no longer prohibit,” Biden said in a statement yesterday. “Criminal records for marijuana possession have also imposed needless barriers to employment, housing, and educational opportunities. And while white and Black and brown people use marijuana at similar rates, Black and brown people have been arrested, prosecuted, and convicted at disproportionate rates.”

Biden will now instruct the Department of Health and Human Services and Attorney General Merrick Garland to quickly monitor the policies that dictate how marijuana is addressed under federal law. The drug is currently classified under the same category as heroin and LSD. Changing that classification “will take some time” after “careful consideration of all of the available evidence, including scientific and medical information that’s available,” a senior federal official said.

A number of states have already legalized marijuana for both medical and recreational use, though it is not yet legal on the federal level.