Next Tuesday, Sports Illustrated will unveil the cover of its 38th-annual Swimsuit Issue. As we mentioned earlier this week, it's one of our favorite days of the year, ranking up there with the Super Bowl and the Fourth of July. Since the first Swimsuit Edition in 1964, 21 American models have graced the cover of the prestigious issue, including five of the last six covers. Will Julie Henderson, Hilary Rhoda, or another American model be able to follow in Brooklyn Decker's footsteps and land a back-to-back win for the USA on the cover of the 2011 issue? Maybe. Scores of jaw-dropping exotic beauties have been featured in the pages of the issue over the last four decades. However, only several dozen of these ladies have hailed from the United States. In anticipation of the 2011 Swimsuit Issue, we emersed ourselves in the SI Vault to round up the hottest American models to ever appear in the magazine. For our purposes, we stuck to just the professional models and excluded the magazine's special-edition spreads of female athletes, cheerleaders, WAGs, and celebrities (sorry for the snub Beyonce, Danica Patrick, and Lindsey Vonn). Here's our look at the 40 hottest Sports Illustrated Swimsuit Models from the United States.

Kim Alexis
Hometown: Lockport, New York

Carol Alt
Hometown: Flushing, Queens, New York

Caprice Bourret
Hometown: Hacienda Heights, California

Angie Everhart
Hometown: Akron, Ohio

Jessica White
Hometown: Buffalo, New York

Alicia Hall
Hometown: Las Vegas, Nevada

Bridget Hall
Hometown: Springdale, Arkansas

Melissa Haro
Hometown: San Jose, California

Melissa Keller
Hometown: Long Lake, Minnesota

Angela Lindvall
Hometown: Midwest City, Oklahoma