In the early days of my genealogy research (before I knew enough to document all my sources), I did a search of the Grasse name, spelling it Grassy, on Ancestry.com and Rootsweb.com message boards. I fould a very interesting post from a 3rd cousin, Richard Grassy! In it, he is trying to discover more information about where his great grandfather John Grassy (my Grandpa George's father) was from. Here's an exerpt:
"I talked to my grandfather and was to get a little more information. Not sure if it is enough to locate the exact St. Peter I am looking for, but I will narrow it down. He mentioned that his father used to live near the border of Austria and Hungary which in the 1880's I think was the Danube River? He said his father could drive horses to Vienna in a day from where he lived. So, I would think that at most he would be as far as 40 miles away. He said he used to cross the river from the Austrian side to the Hungarian side to teach German. . . My map shows some of these towns listed below but does not show any in upper Austria.
Do you have any ideas as to which ones might fit the description? My great grandfather's name on his immigration papers was Johan Grasy, it was changed to Grassy."
The answer from someon who's name I did not document, was even more enlightening:
"There were many places called Szentpeter in old Hungary. . . Since you, however, stated that your ancestral Szentpeter was near Vienna, and as the name of Grazy/Graisy/Grasy is known to exist in the region southeast of Vienna (today split between Austria and Hungary), the most obvious candidate is the place that was called Mosonszentpeter, today's Janossomorja." (Bold is mine)
After a little more research on these town names, I confirmed this to be a town in Moson county called Mosonszentpeter. After amalgamation with nearby Mosonszentjanos and Pusztasomorja, the town today has the name Janossomorja, Hungary.
This town fits the description of its location by Richard Grassy. Mosonszentpeter was to the east of Sopros, Hungary, to the right, near Vienna on the map below. Could this be where my ancestors came from? A definitive answer did not come until a couple years later.