After retiring in 1869, which former secretary of state traveled the world, including a stop in Alaska?

After resigning as leader of the U.S. Marine Band, who gave his first concert with his own band on September 26, 1892? After retiring as a player, Babe Ruth was a first-base coach in 1938 for which other New York team? After retiring as the Dodgers' manager, who guided the 2000 U.S. Olympic baseball team to the gold medal? After retiring from medicine in 1840, who began work in London on his famous thesaurus? Which Australian author followed her 2006 bestseller "The Secret" with "The Power" in 2010? After ruling for 50 years, King George I was assassinated in March 1913, and Constantine I became king of which country? After running fraudulent investment schemes and serving time in federal prison, who was deported to Italy in 1934? Which country is Europe's largest by area after Russia?