But Leonard Saunders, an American immigration lawyer in Washington state, testified before a Senate committee that Canadians could be denied entry to the United States even after cannabis is legalized because it is still considered illegal at the federal level in the United States.
MPs spent a portion of Monday and last week debating the Senate's amendments before 205 of them voted today in favour of rejecting 13 of the proposed changes.
Health Minister Ginette Petitpas Taylor has said the provinces will need two to three months after the bill is passed before they'll be ready to implement the new legalized cannabis regime.
A Canadian flag with a marijuana leaf on it is seen during the annual 4/20 marijuana rally on Parliament Hill in Ottawa, Ontario, Canada, April 20, 2017.
It will not come into fruition until it passes the Senate, and it's not expected to become law until September at the earliest.
"I think it's a great day for Canada", says Senator Tony Dean, the bill's sponsor.
Advocates argued putting the limit at 21 would encourage a black market and drive youths into the hands of criminals.
Justice Minister Jody Wilson-Raybould tweeted that it was a "historic milestone for progressive policy in Canada as we shift our approach to cannabis".
He has insisted his government would move to legalize the production, sale and consumption of the drug this year. We can start to be proactive in public education. "Our plan to legalise [and] regulate marijuana just passed the Senate". "These are good things for Canada".
However, some health experts have anxious that the lower age will encourage use of a substance that can have long-term consequences on still-maturing brains.
Conservative senators remained resolutely opposed to legalization, however, and predicted passage of C-45 will not meet the government's objectives.
"We're going to have all those involved in illegal marijuana peddling right now becoming large corporation", Conservative Sen.