write a brief description of how counties originated in the United States and how they have changed over time.

Explained below

Explanation:

County is a political subdivision that assists the functioning of the government in a State. The geographic region withing a State enjoys certain governmental authority.

There were Thirteen Colonies in United States who were the earliest settlers. Counties formed the local government in those Colonies to provide governance at microcosmic level. The first Counties were created in the Virginia state to provide assistance to Jamestown. It aims to ease the administrative workload.

Post Independence in 1776, the idea of local governments were not introduced. It was under State to determine how they will distribute the powers and its executors which then took the shape of a County in United States. Local government began to take active part in the governance, they began to provide services that were exclusive to a County as well as unincorporated areas.

At present there are 48 Counties in United Sates. Louisiana and Alaska denotes them as Parishes and Boroughs, which are equivalent to a County.

Each county has subdivisions that includes municipalities, unincorporated areas and townships. Power varies from one county to other depending upon the demographic features and duties assigned to it.