Judicial Conference Advisory Committee on Civil Rules, he played a pivotal role in the 1966 revisions to Federal Rule of Civil Procedure 23, which transformed class action practice in the U.S.[3] Kaplan grew up in the South Bronx, graduating from DeWitt Clinton High School at the age of 14.
[1] He then attended City College, graduating in 1929 at the age of 18,[1] and Columbia Law School in 1933,[4] and engaged in private practice until 1942 when he joined the Army.
[2] In 1945, while a lieutenant colonel in the army, Kaplan joined the prosecution team developing the case against the Nazi war criminals.
He co-edited the first process casebook to address the 1938 Federal Rules of Civil Procedure in 1952 with Richard Field.
[7] In 1942 Kaplan married to Felicia Lamport (1916 – 23 December 1999), a political satirist and writer of light verse.