Where did most immigrants come from? 
 Yes, immigration in the 19th & 20th century created a flow of cheap labor, including children and non English speakers. 
 I see. Did people do well as a result of the oil boom and did that cause an increase in population? 
 I don't know about the specifics of where, but I know that both Dutch and English claimed parts of the Delaware River as part of colonialism in the area. 
 Understood. Any more history facts?
Yes, immigration in the 19th & 20th century created a flow of cheap labor, including children and non English speakers.