Two Tachovsky families immmigrated to the United States of America in the 1800s: the family of Thomas Tachovsky and Anna Brozovsky immigrated to Wilber, Nebraska; and the family of Jan Evangeline Tachovsky and Theresa Sekerka immigrated to the Lehigh valley of Eastern Pennsylvania. The former family has privately published their family genealogy. The latter family, from which I am descended, hasn't done one yet.
The last I heard, these two Tachovsky families are distant cousins, the Tachovsky surname having originated in the 1700s. However, this is quite a rumor, since it is at least third-hand news to me, and no one has given me any definite information or documents. A Tachovsky in Czechy is supposed to have the whole family tree (except for possibly the American branches).
If you want to know more about the Tachovskys of Nebraska, please contact one of them directly. I do not know any of them personally, and am probably a stranger as much as you. They are active in the appropriate genealogical societies and I am sure will be happy to communicate with you.
The rest of this page concerns the Eastern Tachovskys.
Ancestry of Jan Evangeline Tachovsky and Theresa Sekerka, founders of the Eastern Tachovsky branch of the United States.