"Here’s how hundreds of thousands of illegal immigrants—mostly Europeans—became legal:
The Registry Act of 1929 allowed immigrants who arrived before 1921 but had no record of their admission to register retroactively, for a $20 fee.
From 1935 to the late 1950s, to keep families together, tens of thousands of Europeans unlawfully in the U.S. were allowed temporarily to go to Canada and reenter the States legally as a permanent resident.
In 1940, Congress authorized the suspension of orders of deportation in cases of hardship, which it defined as “serious economic detriment” to the immigrant’s immediate family. The guidelines have become less generous, but the principle remains in the law."
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