Former first lady Eleanor Roosevelt is remembered as an activist, diplomat and the wife of former US president Franklin D Roosevelt.

But she is seldom thought of as a lover.

In a new novel, American author Amy Bloom explores the rumoured real-life relationship between Eleanor Roosevelt and female journalist Lorena Hickok.

In media reports and history books, the two women have often been described as "close friends".

But Bloom, who has pored through the thousands of letters the women exchanged, says there is no doubt they were in love.

"We have 3,000 letters between them which are warm and passionate and exactly the kind of letters you expect lovers who are still in the first blush of a romance to exchange with each other," she says.

The letters began in 1932 and continued for three decades. At some points in their relationship the women were sending each other two letters a day.

They have been publicly available since the 1970s.

In one, Roosevelt writes, "I ache to hold you close. Your ring is of great comfort. I look at it and think she does love me, or I wouldn't be wearing it."

In another, Hickok tells Roosevelt, "I want to put my arms around you and kiss you at the corner of your mouth."

From poverty to power

Unlike Roosevelt, who grew up in a rich and aristocratic family, Hickok was born in to poverty in rural Wisconsin. She escaped a violent father before forging a career for herself as a journalist.

She was a highly regarded reporter for the Associated Press when she was assigned to cover Eleanor Roosevelt in 1932.

As she grew closer to the Roosevelts, Hickok gave up her job and eventually moved in to the White House — in a room adjoining the first lady's.

While the women were discreet about their relationship, Bloom believes the White House press corps probably knew about it.

"I think it is one of those peculiar times that homophobia was actually a great friend to them," she says.

"Because it would have been shocking to say that the first lady was a lesbian, because it was at that time shocking to say the word lesbian, to even bring it up would be to put yourself in the category of the perverse."

While Eleanor Roosevelt is revered as an influential public figure, her personal life is often overlooked. ( Supplied: FDR Library )

Indeed, the press corps was already used to keeping secrets for the Roosevelts.

The media was complicit in keeping the full extent of Franklin D Roosevelt's disability under wraps — he was largely confined to a wheelchair — and his extramarital affairs, including his rumoured relationship with his secretary Missy Lehand, were also kept quiet.

"Partially he was protected because it didn't feel like it would serve the country or any particular political agenda to open the affair to scrutiny," Bloom says.

"The largely male press, I think, regarded the affair very sympathetically."

As for whether the president knew about his wife's affair, Bloom says it's very likely.

"I'm pretty sure that Franklin knew about the relationship since Lorena was living in the White House and coming to breakfast every morning," she says.

A love story re-imagined

In her novel White Houses, Bloom uses the known facts of Eleanor Roosevelt and Hickok's relationship as a starting point, before branching into fiction.

"I had the wonderful opportunity to create conversations and create characters and create dialogue — the scenes that take place in the kitchen and the living room and bedroom, to which no-one, whether they are a historian or a journalist or a novelist, are privy," Bloom says.

Bloom says she wanted to write about a middle-aged love affair. ( Getty Images: Jeremy Sutton-Hibbert )

In her book, the two middle-aged women embark on a beautiful and sensual love affair. The romance is one of music and cocktails, holidays in open-topped cars and kissing in the garden.

"I really wanted to write about people who were not young and glossy and beautiful," she says.

"I wanted to write about this enduring relationship that begins as a romance, and when the romance cools down, endures as a great and committed and loving friendship."

While the romance between Roosevelt and Hickok is believed to have died down after 1938, the women stayed in correspondence until the first lady's death in 1962.

Roosevelt has been remembered in almost reverent fashion, but Bloom says her book seeks to look beyond the "icon" status to the woman beneath.

"It might be that what we find very hard to believe is the idea that if you are an important and iconic female figure … it is impossible to think that you would have any other interests except being a good mother to the entire nation," she says.

"But it turns out that even good mothers are people, too."

White Houses by Amy Bloom is published in Australia by Allen & Unwin.