The correct answer is: Americans changed the names of towns
When the WWI began, there was a rise of Anti-German culture in the US because of the war propaganda, especially after the US joined the war on the side of the Allies against Central Powers.
Anyone that could be even German-American would be perceived as dangerous. Anything that was from the German Culture had to be removed. Because of that many names of towns were changes, such as Germantown changed to Garland. East Germantown changed to Pershing. Berlin Iowa changed to Lincoln. Berlin Michigan changed to Marne.