If you walked into a high-end social gathering in Manhattan in the late 1800s and shouted the name "Roosevelt," half the room would probably turn around. But they wouldn’t all be the same kind of Roosevelt. It’s one of those weird historical quirks that often trips people up during trivia night or high school history exams. People usually know they were kin, but the specifics of how were FDR and Teddy Roosevelt related are a bit more tangled than a simple father-son dynamic.
They weren't brothers. They weren't father and son.
In reality, Theodore Roosevelt and Franklin Delano Roosevelt were fifth cousins.
To a lot of us today, a fifth cousin is basically a stranger you share a DNA match with on a genealogy site. But for the Roosevelts? It was a tribal identity. They shared the same great-great-great-great-grandparents, Nicholas Roosevelt and Heyltje Jans Kunst. Nicholas was the common ancestor who lived way back in the late 1600s. From him, the family tree split into two distinct branches: the "Oyster Bay" Roosevelts and the "Hyde Park" Roosevelts.
Teddy was the star of the Oyster Bay clan. They were Republicans. Franklin belonged to the Hyde Park group. They were Democrats. It was a family divided by politics but welded together by a massive sense of aristocratic duty and a name that carried a ridiculous amount of weight in New York society.
The Family Tree: More Than Just a Last Name
To really get how these two giants of history viewed each other, you have to look at the geography of their wealth. The Oyster Bay Roosevelts, Teddy’s side, were generally seen as the "older" money, though both sides were incredibly comfortable. They were New York Dutch royalty.
Franklin grew up idolizing Teddy. Most people don't realize that. Even though they ended up on opposite sides of the political aisle, FDR spent his youth trying to mimic TR’s trajectory. He went to Harvard. He served as Assistant Secretary of the Navy. He became Governor of New York. It was almost like a checklist.
But the relationship gets even more "Game of Thrones" when you realize that Franklin didn't just share a last name with Teddy—he married into his immediate family.
Enter Eleanor Roosevelt
This is where the "how were FDR and Teddy Roosevelt related" question gets a second, more intimate layer. Franklin married Eleanor Roosevelt. Eleanor was Teddy Roosevelt’s favorite niece. She was the daughter of Teddy’s brother, Elliott.
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This means Eleanor and Franklin were fifth cousins once removed.
At their wedding in 1905, Teddy Roosevelt actually gave the bride away. Why? Because Eleanor’s father had passed away years earlier. Teddy was the sitting President of the United States at the time, and his presence completely overshadowed the couple. He reportedly told Franklin, "It is a good thing to keep the name in the family." It’s kinda wild to think about a sitting President stealing the limelight at a family wedding, but that was TR for you. He wanted to be the bride at every wedding and the corpse at every funeral.
Two Different Worlds in One Family
While they shared a name, their personalities were night and day. Teddy was a caffeinated explosion of energy. He boxed in the White House. He went on African safaris. He survived an assassination attempt and finished his speech while bleeding. He was the ultimate "Rough Rider."
Franklin was different.
FDR was more calculated, perhaps a bit more "charming" in the traditional sense. While Teddy was loud and physically imposing, Franklin’s strength was in his voice and his ability to project calm, especially after he was paralyzed by polio in 1921.
The Political Rivalry
You might wonder if the Oyster Bay Roosevelts liked their Hyde Park cousins. Honestly? Not always. Especially not when Franklin started winning.
Alice Roosevelt Longworth, Teddy’s daughter and a legendary Washington wit, was famously prickly about Franklin. She viewed him as a "shilled" version of her father. She once said of FDR, "He’s one-third mush and two-thirds Eleanor." The Oyster Bay branch often felt that Franklin was "using" the Roosevelt name to push Democratic policies that would have made the Republican Teddy roll over in his grave.
They were wrong, of course. Teddy was actually quite progressive for his time, often fighting against big trusts and monopolies. But the family feud was real. By the 1930s, the Oyster Bay Roosevelts were largely campaigning against their own cousin. Politics is messy, but family politics? That's a whole different level of drama.
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Why the Connection Mattered for American History
If Franklin hadn't been a Roosevelt, he might never have become President. That’s a bold claim, but the name gave him an instant "brand" before branding was even a thing. Voters in the early 20th century associated the name Roosevelt with strength, reform, and a certain kind of American grit.
When FDR ran for office, he wasn't just a Democrat from New York. He was a Roosevelt.
- The Navy Connection: Both men served as Assistant Secretary of the Navy. This wasn't a coincidence. FDR actively sought the job because it was the same stepping stone Teddy used.
- The New York Governorship: Both used Albany as a springboard to the White House.
- The Rhetoric: Teddy had his "Square Deal." Franklin had his "New Deal." The naming convention alone shows how much FDR was leaning on the legacy of his cousin.
It’s important to remember that during the Great Depression, people were desperate for a leader who felt familiar. The Roosevelt name provided a sense of continuity. Even if the policies were different, the "vibe"—as we’d call it today—was one of aristocratic stewardship.
Common Misconceptions About the Roosevelts
People often think they were uncle and nephew. They weren't. Because Eleanor was Teddy's niece, and Franklin was Eleanor's husband, Teddy was Franklin's cousin-in-law as well as his fifth cousin. It's confusing.
Another big myth is that they were best friends.
They weren't.
They were friendly, and Franklin certainly worshipped the ground Teddy walked on early in his career, but their age gap (Teddy was 24 years older) and their differing political parties meant they didn't hang out on the weekends. By the time Franklin was a major national figure, Teddy had already passed away (TR died in 1919; FDR became President in 1933).
FDR spent a lot of his presidency talking to Teddy's ghost, in a sense. He kept a portrait of TR in the White House. He frequently referenced his "cousin Theodore" when talking about conservation and national parks. He knew that by honoring Teddy, he was solidifying his own place in the American pantheon.
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How to Trace the Lineage Yourself
If you're looking into how were FDR and Teddy Roosevelt related because you're doing your own family research, the best place to start is the "Claes Maartenszen van Rosenvelt" line. Claes was the original immigrant who came from the Netherlands to New Amsterdam (now New York) in the 1640s.
- The Oyster Bay Line: Claes -> Nicholas -> Johannes -> Jacobus -> James -> Theodore "Thee" Sr. -> Theodore Roosevelt.
- The Hyde Park Line: Claes -> Nicholas -> Jacobus -> Isaac -> James -> James -> Franklin Delano Roosevelt.
You can see where they deviate. It happens right at the third generation. One branch stayed focused on business and Manhattan real estate, while the other (Franklin’s side) eventually moved up the Hudson River to Hyde Park and became more "gentleman farmers."
The Lasting Legacy of the Cousins
What’s truly fascinating is how these two men, separated by a few generations and a lot of political theory, redefined the American presidency. Before the Roosevelts, the President was often seen as a figurehead or a servant of Congress.
Teddy changed that with his "Bully Pulpit." He made the President a celebrity.
Franklin took that celebrity and turned it into a permanent fixture of American life through his Fireside Chats.
The relationship between them was a bridge between the 19th-century world of "rugged individualism" and the 20th-century world of the "social safety net." They both believed the government should work for the common man, even if they had very different ideas about how to make that happen.
Without the Oyster Bay cousin paving the way, the Hyde Park cousin might have just been another wealthy New York lawyer. And without the Hyde Park cousin, the Roosevelt name might have faded into the history books as a one-hit wonder of the Progressive Era.
Next Steps for History Buffs
If you want to see the physical reality of this family divide, you should plan a trip to New York. Visit Sagamore Hill in Oyster Bay to see Teddy’s "Summer White House"—it’s filled with taxidermy and books and feels like a Victorian explosion. Then, drive two hours north to Springwood in Hyde Park to see FDR’s estate. The contrast between the two homes tells you everything you need to know about their personalities.
You can also check out the documentary "The Roosevelts: An Intimate History" by Ken Burns. It’s a long watch, but it dives deep into the psychological rivalry between the two branches of the family. Understanding the Roosevelt family isn't just about genealogy; it's about understanding how a single family's ambition shaped the modern world.