You can look up US Census population schedules from 1790-1950. These list the names of household members and some basic information about them. The exact information provided varies by year, but generally includes occupation, marital status, place of birth, parents' places of birth, and year of immigration to US.
The easiest way to find Census records is to look up a person by name. If you only have an address, try searching Directories and News to find names.
Immigration and naturalization records are other possible sources.
Like Census records, it's easiest to find immigration records when you have a name. Searching Directories and News can be helpful if you just have an address.