The Grand Canyon is really grand. When standing on the ridge of the canyon and looking 1 mile (1600m) down to the river Colorado that created all this, you do owe the river a lot of respect. It is possible to walk all the way down and back up in a day, what can be recommended.
Las Vegas is the show and gambling capital of the USA and the Western world. The city is featured in many, many movies and TV series. Las Vegas is a desert city with water coming from Lake Mead.
The Las Vegas strip is the best known with casinos, fancy hotels and top-class resorts. You can also find the Eiffel Tower, Little Venice, a Pyramid and Lady Liberty here. Of course you can get married here with Elvis Presley as your witness.
Los Angeles (aka. City of Angels) is the 2nd largest city in the USA and has a lot to offer, including great shopping (a la Pretty Woman), Hollywood, Venice Beach and sports (L.A. Lakers).
Memphis is home for music legends Johnny Cash and Elvis Presley. Graceland, home and final resting place of the King of Rock and Roll, can be found here.
Nashville is the second largest city in Tenessee and the heart of Country Music. Of course you should listen to the music that inspired so many and visit The Country Music Hall of Fame.
New Orleans is located at the delta of the Mississippi river. It is known for it´s citizens Tow Sawyer and Huckleberry Finn, as well as a lot of classic river boats and Music in the so-called French Quarter.
New York City has a few nick names, for example "The Big Apple", "The City That Never Sleeps" and "The Financial Capital of the World". We cannot list everything that there is to do in NYC, because it is too much. The basics however are the Statue of Liberty, Times Square, Broadway, Little Italy / China Town and the Empire State Building.
Washington DC is the capital of the USA and hosts for example the home of the president ("White House"), the Capitol and Lincoln Memorial. Outside of politics there is the excellent Smithsonian museum.