Short answers, pulled from the story.
A Jewish quota is a discriminatory racial quota designed to limit or deny access for Jews to educational institutions, professions, or public life. Such quotas were widespread in the 19th and 20th centuries across Russia, Germany, Hungary, France, the United States, Canada, Romania, Yugoslavia, and Poland, and were especially common at prestigious universities.
Harvard's president Abbott Lawrence Lowell raised the issue of a 'Jewish problem' after Jewish enrollment grew from six percent to twenty-two percent between 1908 and 1922. Harvard's 1926 announcement of a new admissions policy emphasizing character and personality was widely understood as the formal vehicle for capping Jewish admissions.
On the 25th of April 1933, the Nazi government introduced a 1.5% quota on new admissions of German non-Aryans, primarily targeting German Jews, under a law framed around limiting overall student numbers. Universities with higher Jewish enrollment could be required to reduce that share to a maximum of five percent. After the 30th of July 1939, Jews were barred entirely from German public schools.
In 1935, Yale accepted only five Jewish applicants from a pool of roughly 200. Dean Milton Winternitz reportedly instructed admissions staff to never admit more than five Jews. As a result, Jonas Salk and hundreds of other Jewish applicants enrolled at New York University instead, according to historian David Oshinsky.
Hungary's Numerus Clausus Act, introduced in 1920 under the government of Pál Teleki, required university student bodies to reflect the ethnic composition of the population. Because Jews made up roughly six percent of Hungary's population, the law effectively cut Jewish enrollment from around fifteen percent to six percent. International pressure from the League of Nations led to a partial relaxation in 1928.
McGill University officially adopted its quota on Jewish admissions in 1920, and the policy remained in place until the late 1960s, making it one of the longest-running formal Jewish quotas at any North American university.