The boxer was developed in Germany during the 19th century. The breed was bred from powerful mastiff dogs to create a breed that would excel as a fighter and hunter. The Germans used the dogs to hunt large and fierce game such as wild boars. The name "boxer" refers to the breed's tendency to stand up on its hind legs and batting out its front paws. The breed was brought to America in the 20th century after World War I. The AKC recognized the breed in 1904 and it started rising in popularity by 1930. Today the Boxer is fiercely loyal and is known for their good behavior around kids.
http://en.wikipedia.org/wiki/Boxer_(dog)
http://www.dogbreedinfo.com/boxer.htm
http://www.akc.org/breeds/boxer/