During a westbound Atlantic crossing aboard the RMS Lusitania in September 1914, Field became enamoured with fellow passenger Evelyn Marshall, and proposed to her before the liner's arrival in New York, less than a week after sailing from England.

Already a recipient of substantial money from the estate of his grandfather Marshall Field, on his 50th birthday he inherited the bulk of the remainder of the family fortune.

After his death, his heirs sold the company back to its founders, Richard L. Simon and M. Lincoln Schuster, while Leon Shimkin and James M. Jacobson acquired Pocket Books.

In 1926, one year after his estate was built, Marshall Field partnered with Robert A. Fairbairn, William Woodward Sr., and Arthur B. Hancock to import Sir Gallahad III from France to stand at stud in the United States.

[9] The Marshall Field III Estate is a mansion built in 1925 on Long Island Sound which was designed by architect John Russell Pope.

His widow and third wife, Ruth Pruyn Field, who had previously been married to sportsman Ogden Phipps, died on January 25, 1994, at 86.

By his second wife, of whom he was the second husband, Audrey Evelyn James, whom he married on August 18, 1930, and divorced in Reno, Washoe County, Nevada, in 1934, he left no issue.