Final answer:
Gangs in early 1800s lower Manhattan were primarily formed by Irish and German immigrants facing discrimination and economic hardship. These groups created tight-knit communities that sometimes led to the formation of gangs in response to the challenges they experienced in densely populated cities.
Step-by-step explanation:
The gangs in lower Manhattan during the early 1800s were often formed from various immigrant groups, including but not limited to the Irish and Germans. This era was marked by intense immigration, with a multitude of individuals arriving in search of economic opportunity after the Civil War, through the end of the 19th century, and into the early 20th century. Notably, Irish immigrants faced considerable prejudice, and some turned to forming gangs as a response to the socio-economic challenges they encountered.
In these ethnically segregated neighborhoods, immigrants often faced discrimination and hostile attitudes that were prevalent in cities of the East and Midwest. This xenophobia sometimes resulted in the passage of anti-immigration legislation. The history of intergroup relations reveals that over time, as prejudice against the Irish and German immigrants declined, new groups such as Italian, Eastern European, and Jewish immigrants faced similar animosities.
In summary, while New York City was a melting pot of various cultures and ethnicities, immigrants faced significant adversities, contributing to the formation of ethnic enclaves and, in some instances, gangs as a means to cope and organize within their communities.