It is hard to imagine now, with Asians the fastest-growing racial group in America, but in the first half of the 20th century they were largely blocked from entering the country and prevented from becoming citizens after they arrived. The Chinese Exclusion Act of 1882 had banned the immigration of Chinese laborers, and in 1924, Congress enacted a new set of ethnic quotas dreamed up by eugenicists aimed at maintaining their conception of America as a white and Anglo-Saxon nation. By designating some races as more desirable than others, the law sharply restricted Jewish and Italian immigration — and banned nearly all Asians.

In the years that followed, a small group of Jewish lawmakers fought to abolish the quotas. In 1952, when Congress embarked on its most ambitious overhaul of the country’s immigration system in decades, they recognized their best opportunity in a generation.

Masaoka joined the fray, lobbying for a provision that gave Asians the right to naturalize and for an easing of the nearly comprehensive ban on Asian immigration.

But defeating the overall quota system proved more difficult. With the Red Scare at its zenith, lawmakers were wary of admitting Eastern and Southern European immigrants, whom they associated with radical political activity. And so to the dismay of Jewish leaders, lawmakers refused to abandon ethnic quotas giving preference to countries like Britain.

Nor were African-American leaders pleased. By the end of World War II, more than 250,000 black immigrants from the Caribbean had settled in the United States, mostly in New York City and Chicago, counted within the large quotas of their colonizers, the British, the French and the Dutch. But the 1952 bill aimed to cap this flow of immigrants at 100 a year from each of these European colonies.

Masaoka did not relish having the interests of Japanese-Americans pitted against those of other immigrants. But to secure gains for his community, he decided to abandon the other groups to support what became known as the McCarran-Walter Act.

Winning the right to naturalize was a watershed moment in Asian-American history. But the fight left others bitter. “It is impossible to compute the amount of harm which the Japanese American Citizens League and Masaoka caused to effective opposition to this legislation,” concluded an analysis conducted by the American Jewish Congress.