Pennsylvania is among the top three states in the nation for its number of local governments. Only Texas and Illinois are ahead of us, writes Irina Zhorov for WHYY.

The Keystone State has 4,897 active local governments, according to the 2012 Census of Governments. These include administrations at the county, municipal, school district, and special district levels.

Meanwhile, Philadelphia made the top ten list of most decentralized urban areas in the nation, as measured by the Metropolitan Power Diffusion Index.

How regional governing bodies developed in each state was determined by Article X of the U.S. Constitution, which left the issue up to the states themselves. While some states were more restrictive, Pennsylvania has historically been one of the states that made their formation easy.

As a result, communities in the state broke up into smaller and smaller units over time. Today, all unincorporated land in Pennsylvania is served by a governing body smaller than a county.

Pennsylvania’s geography also facilitated the process, with much of the state being intersected with rivers and physically divided by mountains and valleys which serve as natural separators.

Read more about local governments in WHYY.