Louis Aston Knight (1873–1948) was a French-born American artist noted for his landscape paintings. One of his paintings, The Afterglow, was purchased by U.S. President Warren G. Harding in 1922 to hang in the White House.
In early 1907, Knight met Caroline Ridgeway Brewster (1882-1959), a distant cousin from Rochester, New York, while she was traveling through Europe with her mother. Knight returned to America with Caroline in October; they married in Raritan, New Jersey. The couple settled in Paris, but lived in New York during WWI, moving back again to the United States in 1940 after the occupation of France, where they remained until their deaths.
This letter from the United States Foreign Service in Luxembourg-Ville postmarked November 30, 1949, was sent to Louis Aston Knight's widow in New York City the year after his death. The address--114 East 84th Street--is an eight-floor apartment building built in 1915.
The 4F, 20-gram letter rate and 3F airmail supplement are nicely paid by the 7F 1948 Tourist View sole franking.
A thousand years from now, covers like this will be remembered as relics of the pre-electronic mail era. So you'd better save 'em now!