Question: What is the birthdate of this wife of the 30th President of the United States, whose favorite pet Rob Roy was acquired in 1922?
Context: Rob Roy (1922–1928) was a white male collie owned by Calvin Coolidge.  Coolidge's favorite pet, he was acquired by Grace Coolidge in 1922 after she became enamored with collies, having seen one of the breed perform in a circus.  He later lived with the family in the White House. Wallace McCamant (September 22, 1867 – December 17, 1944) was an American jurist in Oregon.  A Pennsylvania native, he served as the 46th Associate Justice of the Oregon Supreme Court from 1917 to 1918.  Later he served briefly on the United States Court of Appeals for the Ninth Circuit.  As a delegate to the Republican National Convention in 1920, McCamant surprised the GOP leadership by placing the name of Calvin Coolidge into nomination for Vice-President.  Coolidge would become the 30th President of the United States upon the death of President Harding in 1923. John MacGregor (24 January 1825 Gravesend – 16 July 1892 Boscombe, Bournemouth), nicknamed "Rob Roy" after a renowned relative, was a Scottish explorer, travel writer and philanthropist.  He is generally credited with the development of the first sailing canoes and with popularising canoeing as a sport in Europe and the United States.  He founded the British Royal Canoe Club (RCC) in 1866 becoming its first Captain. Samuel Ealy Johnson Jr. (October 11, 1877 – October 23, 1937) was an American businessman and politician.  He was a Democratic member of the Texas House of Representatives representing the 89th District.  He served in the 29th, 30th, 35th, 37th, and 38th Texas Legislatures.  He was the father of the 36th President of the United States, Lyndon B. Johnson and the son of Samuel Ealy Johnson Sr. He was a struggling farmer and cattle speculator who lived in the Texas Hill Country. Thomas R. Fitzgerald, S.J (February 23, 1922 – March 22, 2004) was the sixth President of Fairfield University located in Fairfield, Connecticut from 1973 to 1979 and the 30th President of Saint Louis University from 1979 to 1987. The first inauguration of Calvin Coolidge as the 30th President of the United States was held on Friday, August 3, 1923 at the Coolidge Homestead in Plymouth Notch, Vermont, following the death of President Warren G. Harding the previous evening.  The inauguration marked the commencement of the first term (a partial term of ) of Calvin Coolidge as President.  The presidential oath of office was administered to the new president by his father, John Calvin Coolidge Sr., who was a Vermont notary public and justice of the peace. Rob Roy is a 1922 British silent historical film directed by W.P. Kellino and starring David Hawthorne, Gladys Jennings and Simeon Stuart.  It depicts the life of the early 18th century outlaw Rob Roy MacGregor. Grace Anna Goodhue Coolidge (January 3, 1879 – July 8, 1957) was the wife of the 30th President of the United States, Calvin Coolidge.  She was the First Lady from 1923 to 1929.  She graduated from the University of Vermont in 1902 with a bachelor of arts degree in teaching and joined the Clarke Schools for Hearing and Speech in Northampton, Massachusetts to teach deaf children to communicate by lip reading, rather than by signing.  She met Calvin Coolidge in 1904, and the two were married the following year. The 1960 presidential campaign of John F. Kennedy, a United States Senator from Massachusetts, began on January 2, 1960, when Kennedy formally announced his candidacy for 35th President of the United States, replacing incumbent President of the United States Dwight D. Eisenhower.  Kennedy was nominated by the Democratic Party at the Democratic National Convention of 1960, taking place between July 11 and July 15, 1960.  On July 15, 1960, Kennedy named Senator Lyndon B. Johnson of Texas as his official running mate.  Kennedy and Johnson won the election on November 8, 1960, defeating incumbent Vice President and Republican nominee Richard Nixon, who would later go on to be the 37th President of the United States.  Kennedy and Johnson were sworn in as 35th President and 37th Vice President of the United States on January 20, 1961 respectively.  Kennedy would serve as President of the United States until his death in November 1963. HMS "Leonidas" was a "Laforey"-class destroyer of the Royal Navy.  She was launched on 30 October 1913.  She served in World War I with the 3rd Destroyer Flotilla and as a convoy escort and was broken up in 1922.  The ship was originally named "Rob Roy" but the name was changed after a new naming scheme was introduced to give all ships of the same class names beginning with the same letter.  Overall cost of the ship was £100,000
Answer: January 3, 1879