My grandfather was born in Ireland and lived in a, then Irish neighborhood in Erie Pa. Is there anywhere I can look to find the history of this area in th 1800"s. Thank You Linda Dougan

Friends, can anyone help me with what kind of information I would expect to find regarding an emigrant who came to this country in 1871. I have his name, age and year of birth in Ireland. 1) Would he have filled out some sort of Alien Registration card. How would he have gone about getting his citizenship? 2) Where would I write to in order to get the forms or the information on the forms. 3) Can this information be accessed through Ancestry.com? Any and all help would be greatly appreciated. Thank you, Kathleen