George and Barbara Bush through the years

Jan. 6, 1945: George and Barbara Bush on their wedding day in Rye, N.Y. (George Bush Presidential Library and Museum)

Jan. 6, 1945: The Prescott Bush family at the wedding of George and Barbara Bush. From left, Jonathan, Nancy, George, Barbara, Prescott S., Bush Sr., Dorothy Walker Bush, Prescott Bush Jr. and his wife Beth, and William Henry Trotter Bush (Bucky), Rye, NY. (George Bush Presidential Library and Museum)

Nov. 8, 1966: George and Barbara Bush on the night he was elected to Congress, where he represented Texas' 7th district for two terms. (George Bush Presidential Library and Museum)

FILE: George Bush, then serving as the U.S. ambassador to the United Nations, poses for a photo with his wife, Barbara. (George Bush Presidential Library and Museum)

FILE: George and Barbara Bush in China, where George Bush served as the United States chief of the Liaison Office. (George Bush Presidential Library and Museum)

Jan. 20, 1981: Vice President George Bush and his wife, Barbara, pose with his mother, Dorothy Walker Bush, and several of his siblings and their spouses on Inauguration Day. (George Bush Presidential Library and Museum)

Jan. 20, 1989: President and Mrs. Bush attend an Inaugural Ball at the DC Armory. (George Bush Presidential Library and Museum)

Dec. 17, 1989: Mrs. Bush sits on the floor with her grandchildren and watches Frosty the Snowman in the residential area of the White House. (George Bush Presidential Library and Museum)

Feb. 28, 2002: Former President and Mrs. Bush share a new book in their apartment at the George Bush Presidential Library complex. (George Bush Presidential Library Foundation)

Dec. 23, 2013: Former first lady Barbara Bush and former President George H. W. Bush look on during a ceremony at President Bush's office in Houston. (AP/Houston Chronicle)