Surely you mean German’s chocolate?
The sweet chocolate bar was named in honor of Sam German, its creator, in the 1850s. It is a trademarked name of a particular chocolate product. It has nothing to do with Germany, even though much of the world’s great chocolate is made there.
Baker’s, which was started outside Boston and predates the founding of this country by about a dozen years, is now owned by Kraft. It makes German’s sweet chocolate, which has a cacao content of 48%. Its semisweet chocolate comes in at 54%, which is not much different. As mentioned elsewhere at Ochef, the cacao content of semisweet chocolate in this country extends from the low 40-percent range to the low 60-percent range, depending on the manufacturer. As the number climbs, the chocolate gets a little darker and you get a little less sweetness.
You can absolutely substitute semisweet chocolate for German’s Chocolate on a one-to-one basis. Depending on the chocolate you use, the result may be marginally different, but few people will notice any difference.