Ship passenger lists can provide useful genealogical data, and other related sources can lead to subsequent applications for U.S. naturalization.
This presentation by Dr. Kathryn Marshall will cover the background of U.S. immigration and naturalization through the years, and will give you information on where you can locate the records.
Note: Please enter the building through the Old Foyer (the door east of the main entrance on I Street). This entrance has steps, so contact Beth Daugherty at firstname.lastname@example.org if you need a more accessible entrance. Street parking near the Central Library is free on Sundays.