Yes my Great Grandmother Katherine and her brother John settled in Hammond Indiana, just south of Chicago. The other brother Peter settled in Chicago. But your Peter is a different one. Mine was married to Weronika nee Glowacka. Peter died on June 4, 1944. I sure wish we could have made a connection. But the Mroz name is pretty common, almost like a Polish Smith or Jones. Thanks for sending me a reply. Wish you all the best.