On Christmas Eve 1910, future US President Warren Harding wrote his mistress Carrie Phillips a letter that began: "There are no words, at my command, sufficient to say the full extent of my love for you ... mad, tender, devoted, ardent, eager, passion-wild."
The message is among about 1,000 pages of sometimes steamy love letters between Harding and Phillips that the Library of Congress will put online on July 29 after a 50-year court seal expires.
