>>521253355 (OP)
>Canadians. Duh.
Probably not. In the US it was a small cabal that did it behind the scenes.
"After Kennedy's assassination, Congress passed, and President Lyndon Johnson, signed the Immigration and Naturalization Act. It leveled the immigration playing field, giving a nearly equal shot to newcomers from every corner of the world. The ceremony was held at the foot of the symbolically powerful Statue of Liberty. Yet President Johnson tried to downplay the law's significance.
"This bill that we will sign today is not a revolutionary bill. It does not affect the lives of millions," Johnson said at the signing ceremony. "It will not reshape the structure of our daily lives or add importantly to either our wealth or our power."
Karen Narasaki, who heads the Asian American Justice Center, finds the 1965 immigration overhaul all the more extraordinary because there's evidence it was not popular with the public.
"It was not what people were marching in the streets over in the 1960s," she says. "It was really a group of political elites who were trying to look into the future. And again, it was the issue of, 'Are we going to be true to what we say our values are?'"
In 1965, the political elite on Capitol Hill may not have predicted a mass increase in immigration. But Marian Smith, the historian for Customs and Immigration Services, showed me a small agency booklet from 1966 that certainly did. It explains how each provision in the new law would lead to a rapid increase in applications and a big jump in workload -- more and more so as word trickled out to those newly eligible to come. Smith says a lifetime of immigration backlogs had built up among America's foreign-born minorities. These immigrants would petition for relatives to come to the United States, and those relatives in turn would petition for other family members."
https://www.npr.org/2006/05/09/5391395/1965-immigration-law-changed-face-of-america