Stewart Prestley Blake was born in Jersey City, N.J., on Nov. 26, 1914, to Herbert Prestley Blake and Ethel (Stewart) Blake. He grew up in Springfield, where his father worked for the clock manufacturer Standard Electric Time Company; his mother was an automobile aficionado who encouraged her sons’ fascination with cars. He bought a Model T Ford by the time he was 16, using earnings from a newspaper route. (Another brother, Hollis, died at age 2.)
Mr. Blake attended Trinity College in Hartford, Conn., for a year before returning to Springfield to open his ice cream store with his brother Curtis.
The Blake brothers closed the shop during World War II to join the war effort. Mr. Blake went to work for what is now Westinghouse Electric Corporation, tracking down elusive electronic equipment and delivering it to wartime manufacturers. (Curtis Blake served in the Army Air Forces in Britain.)
After selling Friendly in the 1970s, Mr. Blake traveled the world by sailboat and Concorde jet and cultivated his collection of classic cars, which at its peak included about two dozen Rolls-Royces. One of them, he wrote, appeared in the Liza Minnelli movie “Tell Me That You Love Me, Junie Moon” (1970), in which he made a cameo appearance as a chauffeur.
Mr. Blake commemorated his 100th birthday in 2014 by building a modernized replica of Monticello, Thomas Jefferson’s Virginia plantation, in Somers, Conn. Costing almost $8 million to build, the mansion sold at auction for roughly $2.1 million in 2016.
His first two marriages, to Della Deming and Setsu Matsukata, ended in divorce.
Mr. Blake died in a hospital in Stuart, where he lived. In addition to his son, he is survived by his wife, Helen Blake; a sister, Betsy Melvin; a daughter, Nancy Yanakakis; several stepchildren; 16 grandchildren and step-grandchildren; and 12 great-grandchildren.
“I started small, worked hard, and succeeded beyond my wildest dreams,” Mr. Blake ruminated at the end of his memoir. “I got out of the ice cream business and was sitting pretty until I had to get off the couch and back into the fray. That battle’s over. I’m 96 and I’m officially retired. Maybe.”