With a POD of 1810, have America own British Columbia, Alberta, Baja, Sonora, Liberia, Cuba, the Philipines, all of the Smaller Pacific Islands and hold them to this day. Japan has to be an American puppet. Major events, like Pearl Harbor, WWI, 1812, the Civil War, ect, must still happen. Also, America itself must keep its current government system and allow some basic forms of Democracy in its Empire.