Who was the first Chasidishe Rabbi to settle in the USA? Where did he settle?
Rebbe Eliyahu Yosef Rabinowitz Lintz – Slavita (Buffalo) Rebbe
The Rebbe came to the United States in 1899 from Russia and settled on the Lower East Side. He later (1910) moved to Buffalo and headed the Jefferson Street Shule. In addition to his own great genealogy the Rebbe was the brother-in-law and chavrusa (study partner) of the renowned Rebbe Mordechai Dov of Hornisteiple.The Rebbe appears to be the first Admor to be buried in the United States.
This article (PDF) says:
Credit for being the first "legitimate" Hasidic rebbe to settle in the United States appears to go to the Ukrainian Twersky family. R. David Mordecai Twersky, a descendant of R. David Twersky, the Tolner Rebbe, settled in New York in 1912.
Earlier in the article, though, he mentions reports from 1893 in New York and 1894 in Baltimore of people giving out kameyos (amulets) and such; whether they were genuine rebbes or impostors, though, I don't know.
The first Chasidic Rebbe to come to America was R. David Mordecai Twersky who came in August of 1913.
The First American Chasidic Rebbe, I think would have to go to Grand Rabbi Pinchas Duvid Horowitz, the founder of the Boston Chasidim. He arrived in America via Israel and Europe in 1915.
The First American Chasidic Rabbi, would be Rabbi Abraham Ash,who served as Rabbi in New York from 1860. http://www.tzemachdovid.org/gedolim/jo/tpersonality/rjj.html