The plessy decision had tremendous effect in society at large at the time as it legitimized racial segregation on an institutional level.
By separating public facilities such as schools and going as far to even exclude black people from transiting public space like many beaches, restaurants and hotels, African-American institutions were effectively put at a huge disadvantage in every regard. Some of the consequences were a massive peak in aliteracy within the black community, for example, and the denial to their political leaders from continuing to advance in a system that removed their ability to further participate. In the south, they also were almost completely erased from voting registrations.
The reason for the expansion to the thirteen colonies was for religious freedoms as well as other freedoms. Without religion perhaps they may have neverbranched out.
