There are a ton of memorials and museums here in the States. Here are a few that I can think of off the top of my head. They are mostly Navy related though.
U.S.S. Intrepid Air and Sea Museum, New York City, several ships and a submarine.
U.S.S. New Jersey BB-62, Camden, New Jersey,
Patriots Point, Charleston South Carolina, has the U.S.S. Yorktown (WWII carrier), a couple of other ships and a sub, as well as Vietnam Era firebase set up on the shore.
There is a museum in Aberdeen Maryland dedicated to armor and artillery. They even have a railroad gun there.