Among his large and prominent family were uncles Franklin Delano Roosevelt (who was three years younger than Tadd), who later became President of the United States, and Colonel John Jacob "Jack" Astor IV, who died during the sinking of the RMS Titanic.

Their kinship led to Franklin often being mockingly referred to as "Uncle Frank" while the two attended Groton together.

[3] On June 14, 1900, while still a student at Harvard, Roosevelt married 19-year-old Sadie Messinger (c. 1880–1940) without the consent of his father Rosey.

"[8]) Rosey unsuccessfully attempted to have the marriage annulled,[6] and both the Roosevelt and Astor families viewed the union as disgraceful.

[10] A court soon granted $625 (equivalent to $14,864 in 2023 dollars) per month alimony to Sadie, pending settlement of the divorce.

At the time, Tadd was reported to be the Floridian paying the highest income taxes, having a $12,000,000 fortune (equivalent to $285,381,818 in 2023 dollars).