The solstice is more than a week away, but as I will be traveling at that time I am sharing this information now about the Cancerian president featured in the Lessons. Leo Herbert Hoover, Virgo William Howard Taft, Libra Dwight D. Eisenhower, Scorpio Warren G. Harding, and Capricorn Richard M. Nixon all are mentioned in the Lessons, and most have their full natal charts included. Lacking a Sagittarian president to include, Winston Churchill will be featured instead as a person well known to many presidents and included among the BOL charts.
Here is a link to a brief biography of Coolidge from the White House website on presidential history:
https://www.whitehouse.gov/about-the-white-house/presidents/calvin-coolidge/