It was early evening when Michael Feighan arrived at the White House on May 7, 1965. A tall, dour Democratic congressman from Ohio, Feighan had an important meeting with President Lyndon B. Johnson.

For months, Johnson and his aides had been hounding Feighan over his resistance to one of the president’s top priorities: passing the most consequential immigration bill in nearly half a century. The proposed law would abolish the 1924 National Origins Act, which put in place a system of ethnic quotas to codify America as a white, Protestant nation. The 1924 system greatly curbed the entry of Jewish, Italian, African and Asian immigrants while offering far more slots to immigrants from Northern Europe.

To Johnson, these quotas were nakedly unjust, akin to the Jim Crow laws restricting the political rights of black Americans in the South — another system that he was trying to dismantle.

But Feighan was nervous. If the country was going to get rid of the quotas, he believed, it still needed a way to control its racial makeup.

And so he offered a compromise: What if the country prioritized entry for people with family already in the United States? This way, Feighan reasoned, the country’s ethnic balance could change only so much. Since most Americans were white, their family members abroad would also be white.

Johnson accepted the deal, which avoided scaring off pro-immigration liberals while easing the concerns of immigration restrictionists in Congress. Four months later, at the foot of the Statue of Liberty, the president signed the compromise into law as the 1965 Immigration and Nationality Act, abolishing the 1924 quotas. “This bill that we will sign today is not a revolutionary bill,” he promised. “It does not affect the lives of millions.”