The Gaßmann name has been occurring in Switzerland since the 1300-s. My own ancestors emigrated from the Zurich area to Stuttgart, Germany, in 1667. Another concentration of the name occurs in Northern Alsace, showing up at about the same time in Birlenbach, Bas-Rhin. There are other pockets of the name around Stuttgart, apparently predating the arrival of my 6G-grandfather. Through subsequent migrations the name now occurs in Australia, the United States, Canada, and so on. The two main spelling variants are "Gassmann" and "Gassman".
I am mostly interested in the early history and would love to put together a tree showing the decendance from the earliest bearer of the surname. Other contributions are of course also welcome.