Calvin Coolidge, Jr. writing his grandfather John Coolidge: March 31, 1918.

Nine-year-old Calvin, Jr. writes to wish his grandfather a happy 73rd birthday. The boy notes that his older brother, John, is sick with “the grippe” and that “most everybody has the grippe.” The grippe that he refers to is likely the first wave of the 1918 influenza pandemic. The virus was epidemic in the Midwest and on the East Coast by April 1918.