When the U.S. Congress passed—and President Lyndon B. Johnson signed into law—the Immigration and Naturalization Act of 1965, the move was largely seen as symbolic."The bill will not flood our cities with immigrants,” lead supporter Sen. Edward “Ted” Kennedy (D-Mass.) told the Senate during debate. “It will not upset the ethnic mix of our society. It will not relax the standards of admission. It will not cause American workers to lose their jobs.”That sentiment was echoed by Johnson, who, upon signing the act on October 3, 1965, said the bill would not be revolutionary: “It does not affect the lives...