On September 9, Queen Elizabeth II became the longest-reigning British monarch. Since she came to the throne in 1952, 10 U.S. presidents have been elected -- and Elizabeth has met with all of them except Lyndon B. Johnson.
Years in office: 1929 - 1933
Herbert Hoover finished his tenure as President long before Queen Elizabeth ascended the throne. However, the opportunity arose in 1957 for a meeting between the two during a royal tour of the United States when the British monarch spoke at a luncheon held at the Waldorf Astoria Hotel. This first meeting is pictured here: Hoover is seated to the Queen's right.
Years in office: 1945 - 1953
During a state visit to the United States in 1951, the then-Princess Elizabeth and her husband Prince Philip were received in Washington by former President Harry Truman and his wife Bess. Truman is the only U.S. President the Queen met while she was a princess.
Dwight D. Eisenhower
Years in office: 1953 - 1961
Dwight D. Eisenhower was the first serving President who Elizabeth II met during her reign; he was also her host during her first state visit to America in 1957. They also met during a visit to Canada two years later in 1959. Representing Canada and as head of the Commonwealth, the Queen welcomed Eisenhower to the country before they formally opened the St. Lawrence Seaway with a short cruise aboard the royal yacht, Britannia.
John F. Kennedy
Years in office: 1961 - 1963
Amid much fanfare and huge media interest, President John F. Kennedy was a dinner guest along with his wife, Jackie, at Buckingham Palace in June 1961. He later wrote that he would "cherish the memory of that delightful evening," in a birthday letter written to the Queen. He added: "The people of the United States join with me in extending to your Majesty and to the people of the Commonwealth best wishes and hearty congratulations on the occasion of the celebration of your birthday... May I also at the same time say how grateful my wife and I are for the cordial hospitality offered to us by your Majesty and Prince Phillip during our visit to London last Monday. We shall always cherish the memory of that delightful evening."
Years in office: 1969 - 1974
Former President Richard Nixon met Queen Elizabeth in Buckingham Palace during an informal visit to the UK shortly after becoming the 37th U.S. President in 1969. The Queen prepared signed photographs of herself and Prince Philip as a small memento of the meeting. Nixon also brought a signed headshot, but said: "I didn't bring my wife along this time, 'cause this trip was so hurried. But we just had a picture taken of the two of us, I would like to send you one of that because it would be much more pleasant to look at the two of us." Laughing, the Queen responded: "That's very nice of you."
Years in office: 1974 - 1977
This White House file photograph, provided courtesy of the Gerald R. Ford Library, shows former President Gerald Ford, right, and Queen Elizabeth dancing during the state dinner in honor of the Queen and Prince Philip at the White House, on July 17, 1976 in Washington.
Years in office: 1977 - 1981
During a 1977 dinner of foreign heads of state at Buckingham Palace, former President Jimmy Carter described the home of the British monarch as "one of the most beautiful places I've ever seen. And I think the whole royal family was there... I had a good place to sit -- I was between the Queen and Princess Margaret and across the table was Prince Charles and Prince Philip and the Queen Mother." He continued: "Well, one of the things I told Queen Elizabeth was how much the American people appreciated her coming over last year to celebrate our 200th birthday. And she said that it was one of the warmest welcomes she'd ever received."
Years in office: 1981 - 1989
The Reagans were the first U.S. family to be overnight guests of the sovereign at Windsor Castle in 1982. In his memoirs, "An American Life", Reagan recalled his stay with the British royal family. "There were many, many small moments that made my job fun ... Landing in a helicopter on the lawn of Windsor Castle for a fairytale visit with Queen Elizabeth and the royal family. The highlight of our stay there came when the Queen and I went horseback riding together and Nancy and Prince Philip took a horse-drawn carriage ride. I must admit, the Queen is quite an accomplished horsewoman. We will always remember our visit to Windsor Castle because of the Queen's and Prince Philip's warmth and welcoming hospitality -- they could not have been more gracious."
George H. W. Bush
Years in office: 1989 - 1993
Former President George H.W. Bush visited the Queen at Buckingham Palace in 1989 while in May 1991, she was guest of honor at a state dinner in the White House. The pair exchanged toasts about the legacy of human rights and the rule of law bequeathed upon the United States by Great Britain. Meanwhile, the Queen spoke about her previous visits to the White House, and the history of diplomatic relations between the two countries. Bush said during his welcome address: "We have got a lot of things in common. Americans share the Queen's love for horses ... Most of all what links our countries is less a place than an idea. The idea that for nearly 400 years has been America's inheritance and England's bequest. The legacy of democracy, the rule of law and basic human rights."
Years in office: 1993 - 2001
Former President Bill Clinton met the Queen more than once during his tenure, taking tea with her at Buckingham Palace in 2000 and also in 1994 at a service to mark the 50th anniversary of the D-Day landings in Normandy. He recalled the occasion fondly saying: "She's a highly intelligent woman who knows a lot about the world ... I always marvel when we meet at what a keen judge she is of human events. I think she's a very impressive person. I like her very much." During a trip to Europe in 2000, Clinton said he drank a little coffee as they talked while former first lady Hillary Clinton sipped tea. The former President said he noticed that although the Queen's hair had turned gray, she had what he described as "youthful eyes." He added: "She has these baby blue eyes, just piercing."
George W. Bush
Years in office: 2001 - 2009
George W. Bush visited Britain on an official state visit in 2003, while the Queen went to the United States in 2007 to celebrate the 400th anniversary of the founding of Jamestown. During his welcome speech, President Bush fluffed his lines and said: ''You helped our nation celebrate its bicentennial in 17-- " Realising his mistake of suggesting the then 81-year-old queen had been on the throne since the 18th century, Bush turned to the monarch and winked at her. Later Bush said she gave him "a look that only a mother could give a child." Here they are pictured in June 2004 in Arromanches, France, watching a flypast by the Red Arrows during 60th anniversary commemorations of the D-Day landings.
Years in office: 2009 - present
"There's one last thing that I should mention that I love about Great Britain, and that is the Queen," U.S. President Barack Obama said at the end of his joint press conference with then-British Prime Minister Gordon Brown during his visit to the UK in 2009. "And so I'm very much looking forward to meeting her for the first time later this evening. And as you might imagine, Michelle has been really thinking that through because I think in the imagination of people throughout America, I think what the Queen stands for and her decency and her civility, what she represents, that's very important." Later, during a reception for G-20 leaders, Michelle Obama was seen to take the unusual step of putting her hand briefly on the back of the Queen. This was against protocol but the monarch seemed to have reached out her hand first and didn't appear bothered by the First Lady's gesture.