I found John Thomas of Ridgeville in an 1852 head of family index of Hamburg, Germany, ship departure lists (copy attached). It gives his origin in Bohemia as Chotzen. That's a German spelling of Chocen, near Vysoke Myto, about 90 miles east of Prague in the Usti nad Orlici district of the Pardubicky region (see attached map). Many of the first Czech immigrants starting about 1850 came from this region. It's fortunate that the emigrant departure lists from Hamburg survived and that Jan Tomas departed from there instead of Bremen (Bremen departure records were destroyed in WWII bombing raids).

On checking the Chocen parish registers, I find daughter Katerina Tomas, born 16 Aug 1839, to father Jan Tomas (son of Jan Tomas and Anna Plecharzh [aka, "Plechash" in Americanized spelling]) and mother Cecilie (daughter of Frantisek Houdek and Cecilie Koutnik). It's the second record on this page from the free familysearch.org site:

https://familysearch.org/pal:/MM9.3.1/TH-1-19257-47400-47?cc...

The writing is in an old script known as Kurrent which has some big differences from standard English cursive writing (letters b, d, e, n, r, and s are especially hard to decipher without some training and practice).

Jan Tomas and Cecilie Houdek were married 23 Oct 1838 at Chocen, see first record on page at:

https://familysearch.org/pal:/MM9.3.1/TH-1-19257-44376-30?cc...

Their son Jan Tomas (John Thomas Jr.) was born 6 Nov 1845 at Chocen (source: Zamrsk regional archive website "Matriky" books, image filename 2103_00074.jpg -- not attached).