Calvin Coolidge to work jointly with Edward T. Clark, a Massachusetts Republican organizer whom he retained from his vice-presidential staff, as Secretaries to the President (a position equivalent to the modern White House Chief of Staff). Perhaps the most powerful person in Coolidge's Cabinet was Secretary of the Treasury Andrew Mellon, who controlled the administration's financial policies and was regarded by many, including House Minority Leader John Nance Garner, as more powerful than Coolidge himself. Secretary of Commerce Herbert Hoover also held a prominent place in Coolidge's Cabinet, in part because Coolidge found value in Hoover's ability to win positive publicity with
Calvin Coolidge To extend an olive branch to Latin American leaders embittered over America's interventionist policies in Central America and the Caribbean, Coolidge led the U.S. delegation to the Sixth International Conference of American States, January 15–17, 1928, in Havana, Cuba, the only international trip Coolidge made during his presidency. He would be the last sitting American president to visit Cuba until Barack Obama in 2016. For Canada, Coolidge authorized the St. Lawrence Seaway, a system of locks and canals that would provide large vessels passage between the Atlantic Ocean and the Great Lakes. In the summer of 1927, Coolidge vacationed in