But what about Bess and Harry Truman? Public displays of romance do not necessarily come to mind. But, as newly released letters written by Bess Truman show, their relationship was one of the most endearing in U.S. presidential history.
Eight letters, revealed this week to the media for the first time ever by Truman's eldest grandson, Clifton Truman Daniel, shed insight into the intimate and close relationship shared by the Truman couple, who met at Sunday school when Harry was 6 and Bess was 5.
"He recalled in his memoirs, walking in and seeing this blue-eyed, blond-haired little girl, and he was just smitten," Daniel said. "He basically carried a torch for her from then on, all through grade school and high school.
"As far as we know, she had one or two other suitors, but he never looked at another woman from the age of 6 on."
Twenty-nine years later, while overseas after the end of World War I, Truman implored Bess to marry him.
"Please get ready to march down the aisle with me just as soon as you decently can when I get back," he wrote on Feb. 18, 1919.
"I haven't any place to go but home and I'm busted financially but I love you as madly as a man can and I'll find all the other things. We'll be married anywhere you say at any time you mention and if you want only one person or the whole town I don't care as long as you make it quickly after my arrival," he wrote.
In response, she wrote back March 16, 1919, "You may invite the entire 35th Division to our wedding if you want to."
They were married June 28, 1919. Their only child, Mary "Margaret", was born Feb. 17, 1924. Clifton T. Daniel, an author and journalist, is Margaret's eldest son.
Harry and Bess Truman remained married for more than 50 years, until his death at age 88.
During Truman's senatorship from 1934 to 1945, the entire Truman family would stay in Washington, D.C., from January through June. But, for the remainder of the year, Bess and Mary would head back to Independence, Mo. To keep in touch, Harry and Bess would write each other thousands of letters.
Between 1910 and 1959, the couple would write more than 3,000 letters chronicling for each other the details of their days spent separately, often discussing the same matters that ordinary husbands and wives would today -- house pests, hair cuts and the weather.
In one letter dated July 16, 1923, after Harry had taken off for the Missouri National Guard training camp at Fort Leavenworth, Kan., as he did every July, Bess wrote to her husband:
"Dear Pettie -- I hope you didn't run into the rain we had about five-thirty -- It didn't last long but it was good and wet while it did last. It is now 10:20 and I am in bed. There was a big black bug on my bed when I turned the sheet down and I had to kill it myself -- but that wasn't the first time I had wished for you."
Bess' hair was a frequent motif in their letters. Harry had wanted her to keep the long golden curls she first wore when he fell in love with her in Sunday school.
On July 7, 1925, Bess wrote to Harry: "Nellie Noland has had her hair cut and she looks perfectly fine. Ethel is going to do it this week. ... I am crazier than ever to get mine off. Why won't you agree enthusiastically? My hair grows so fast, I could soon put it up again if it looked very badly. Please! I'm much more conspicuous having long hair than I will be with it short."
Two days later, Harry wrote back: "Say, if you want your hair bobbed so badly, go on and get it done. I want you to be happy regardless of what I think about it. I am very sure you'll be just as beautiful with it off and I'll not say anything to make you sorry for doing it. I can still see you as the finest on earth so go and have it done. I've never been right sure you weren't kidding me anyway. You usually do as you like about things and that's what I want you to do."
While the letters between them discuss rather ordinary matters, presidential historian Robert Dallek said they are a "rich window" into their lives.
"These letters are very important on two counts," he said. "They can give you an idea of the private life the president had, a greater, fuller sense of what his personality was, and the influence his spouse may or may not have had on him."
"Secondly, the year the president would write about public issues and policy questions, it just enriches the record of the historian to let him know what was going on in his mind. In general, they tell you a great deal about their personality."
Harry Truman had a "moral compass that was much stronger than many presidents that came after him," Dallek said.
These letters and his loyalty to his wife, he said, illustrate that "without question."
Cokie Roberts, political analyst, commentator and author of several books on influential women in U.S. history, said first ladies often say much about a president's own values.
Bess Truman, she said, was a smart woman with a good sense of humor, who didn't like to spend a lot of time in Washington and kept the president grounded.
Born Feb. 13, 1885 as Elizabeth Virginia Wallace, she was the oldest of four children born to David Willock Wallace and Madge Gates Wallace. Her father held several public offices in Missouri, including county treasurer, and deputy surveyor in the Kansas City office of the United States Bureau of Customs.
Bess had a reputation as a tomboy while growing up. After graduating from Independence High School in 1901, she later studied language and literature at Barstow, a girl's finishing school in Kansas City, Mo. After graduating, she helped her widowed mother run the household.
As a senator's wife, Bess read the Congressional Record, edited Harry's speeches and served as a confidante and political adviser. She provided her husband with so much help, Harry placed her on his Senate office's payroll. Bess had advised her husband on his Senate reelection campaign in 1940, grandson Daniel said.
She became "second lady" when Harry was elected vice president to Franklin D. Roosevelt in 1945.
When Bess Truman became first lady in 1945, after Roosevelt's sudden death left her husband as president, she personally directed White House social events, served as honorary president of the Girl Scouts, the Women's National Democratic Club and the Washington Animal Rescue League, as well as the honorary chairman of the American Red Cross and many other organizations.
"She understood politics, she followed the game, she was good at it," Daniel said. "She liked living it vicariously through him and she would give him advice, back him up, ask him what was happening. She was by no means running the country from Independence, but she was interested, she was engaged, and he trusted her opinion."
Analyst Roberts said, "The first lady is always something of an enigma. She is such an incredibly influential person, who is not elected and can't be fired. Her greatest influence is her influence on the most powerful man in America. The wife is often the only one that can tell him the truth."
Michelle Obama, who worked as a lawyer, has captured the U.S. public's fascination, with the media covering everything from her fashion sense to her family roots.
Since moving to the White House nine months ago, Michelle has kept a high public profile, hosting cultural events, advocating on behalf of children's health and eating habits, and recently traveling to Copenhagen with the president to support Chicago's bid for the 2016 Olympics.
"As far as the Obamas go," Dallek said, "They seem to be a strong family. It's not only that he has a good marriage, but he's attentive to his children. It resonates with lots of people. He's in a good marriage, he's a family man."
Former first lady Laura Bush also boosted her husband's image, Roberts said.
"One of the reasons people liked George W. Bush was that he was married to Laura Bush. She's very attractive, smart, funny, down-to-earth but very intellectual. The fact that he married someone that substantial made people like him better."
Bush, a former elementary school teacher, advocated on behalf of children's education, human rights and foreign affairs, becoming a vocal critic of Burma's military regime.
And, although then-first lady Hillary Clinton was her husband's "key adviser" and there was "tremendous respect for one another's skills and abilities," Roberts said, the Clintons had a tempestuous private relationship that became public, after the president's affair with a White House intern.
Dallek said, "It was a source of great distress and humiliation for Hillary and landed him in the hot seat by getting him impeached."
"It has an impact on the way people view a president -- if he's known as lacking scruples or is known as being disloyal to his wife. It makes some people quite angry, if a president is known as something other than the straight and narrow. We profess to be a nation with family values," Dallek said.
While the Trumans' relationship was scandal free, Bess Truman preferred to keep her life private.
Grandson Daniel said, "Grandpa was an open book" who saved "every scrap of paper, every bill, every letter."
But his grandmother, he said, was a "very, very private person who thought her business was her own damn business and that was it."
While thousands of Harry Truman's notes and letters are publicly available at the Harry S. Truman Library & Museum in Independence, Mo., Bess burned most of hers in 1955.
"One evening in 1955, around Christmastime, Grandpa came home and found her in front of the fireplace with a roaring fire, throwing in bundles of her letters to him," Daniel said. "And he stopped her and said, 'Bess! Dear God, what are you doing, think of history!' And she said, 'Oh, I have!' and kept throwing letters in the fire. She destroyed almost all of them."
Her reticence was because of, in part, her father's suicide when she was 18, Daniel writes in the fall 2009 issue of Prologue magazine.
"She adored him, and his death was sudden, unexpected, heartbreaking, and in that day and age, shameful," he wrote. "She never spoke of him. What thoughts and feelings she had were reserved for family and close friends, and she was determined to keep it that way."
But, Daniel said, his grandmother overlooked 180 letters that had been hidden away in books, or in the back of desk drawers. They were discovered in the early 1980s by Truman library archivists.
Daniel's mother Margaret, who owned the letters until her death last year, included some of them in her 1985 biography of her mother. In 1998, 15 were put on display at the library. Daniel is working on a book of his own, on his grandmother's letters, but it will be another four years before all of them will be open to the public.
Daniel said although, as a child, he knew his grandmother as a stern lady who he feared disobeying, her letters showed him the softer, playful side he had heard stories about while growing up.
"I just started laughing when I was reading them for the first time," he said. "It was fun to finally confirm -- she has a sense of humor, she's fun to listen to, and also to listen on paper to a young Bess Truman. I only knew the 80-year-old Bess Truman, I didn't know the 40-year-old Bess Truman."
Daniel said his favorite letter is the one in which Bess recalls killing a bug in her bed.
"I am the bug killer in my house," he said, laughing. "And if my wife is alone without me, then she'll have to do it on her own."
While he and his wife don't write letters to each other, they do text message.
"My grandparents' letters are the 1920 equivalent of texting or e-mailing," he said.
This story has been updated to reflect Mary Margaret Truman as "Margaret".