Why would people prefer to settle with others from their original homes?

Creates a sense of security and comfort.

In the case of the US, original colonies were set up in the likeness of European cities and countries. The Spanish and French set up colonies reflecting the power of the Catholic Church and the culture found in their home countries. This was even more true in the English colonies as they did not want to interact with the Native Americans. They created settlements with names that referred back to home such as New England as a colonial region. They brought their religion, language, and families to continue their norms of home. With every immigrant group that came, ethnic neighborhoods were created to create a sense of home. This is why major US cities still have Italian, Irish, Jewish, and Chinese neighborhoods for example.

It enhances a feeling of social security. Most of these people are kins and despite the disintegration of mechanical societies and emergence of organic society, kinship ties still remain an important part of the society.