One of the best places to look for names with American associations is past U.S. leaders. The presidents' first names have largely been classics (John, James, William, etc.) but several -- like Millard, Rutherford, and Woodrow -- have really stuck out. Notable presidential surnames include Franklin, Harrison, Jefferson, Kennedy, Reagan and Truman. Finally, some presidential surnames -- like Cleveland, Jackson, Lincoln, and Madison -- are place names as well, which logically brings us to...
The biggie in this category is, of course, America (which was likely inspired by the name of explorer Amerigo Vespucci.) State names that have been used as baby names include Virginia, Georgia, Arizona and Montana, and city names that have been used in the same way include Cheyenne, Boston, Raleigh and Helena.
People in the U.S. tend to greatly value their freedom -- so much so that Freedom is sometimes used as a name. The Pledge of Allegiance ends with two more "value" words that have also been used for newborns: Liberty and Justice. And, though there aren't any Puritans left, Puritanical names (like Reliance, Patience, Temperance and Prudence) were often bestowed upon babies in colonial America.
Elvis Presley and Marylin Monroe, recognized worldwide, are perhaps America's most well-known symbols. But don't forget the many others, like writers Ernest Hemingway and Emily Dickinson, activists Martin Luther King and Susan B. Anthony, entertainers Shirley Temple and Marlon Brando, and athletes Lance Armstrong and Jackie Joyner-Kersee.
This is a special subset of names with a distinctly American sound. Some of the best examples of "cowboy names" are Cody, Dale, Maverick, Travis, Wyatt and Zane. Western names that also happen to be place names include Austin, Dakota, Dallas and Tex.