Passenger manifests show Frederick entering the US on 24 Jun 1913 with the name of Fedor Cichy. Cichy was his stepfather's surname. He must have changed his name within the next few years as the name on his 1919 marriage license is Sowienski. At some later point that became Sowinski.
The passenger manifest lists his home as Zborow, whereas his death certificate lists it as the larger nearby town of Stopnica.