Your query is on Slovakia's board and it should be on Poland's. You might also want to post on Illinois's board.
You do need to have a precise location to proceed with the research. Most of US documents should have a place of birth.www.rootsweb.com/~polwgw/index.htmlhttp://genforum.genealogy.com/poland/www.surnamenavigator.org
distribution of SIEDLECKI surname holders in Poland:http://www.moikrewni.pl/mapa/kompletny/siedlecki.htmlhttp://www.moikrewni.pl/mapa/kompletny/urban.html