Jefferson County is the most populous county

County (United States)

In the United States, a county is a geographic subdivision of a state , usually assigned some governmental authority. The term "county" is used in 48 of the 50 states; Louisiana is divided into parishes and Alaska into boroughs. Parishes and boroughs are called "county-equivalents" by the U.S...

 in the U.S. state of Alabama

Alabama

Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

, with its county seat

County seat

A county seat is an administrative center, or seat of government, for a county or civil parish. The term is primarily used in the United States....

 being located in Birmingham

Birmingham, Alabama

Birmingham is the largest city in Alabama. The city is the county seat of Jefferson County. According to the 2010 United States Census, Birmingham had a population of 212,237. The Birmingham-Hoover Metropolitan Area, in estimate by the U.S...

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As of the 2010 U.S. Census, the population of Jefferson County was 658,466. Jefferson County is the principal and most populous county in the Birmingham metropolitan area

Birmingham–Hoover–Cullman Combined Statistical Area

The Birmingham-Hoover-Cullman, AL CSA sometimes known as Greater Birmingham, is made up of 8 counties in Central Alabama....

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Jefferson County was established on December 13, 1819, by the Alabama Legislature

Alabama Legislature

The Alabama Legislature is the legislative branch of the state government of Alabama. It is a bicameral body composed of the Alabama House of Representatives, with 105 members, and the Alabama Senate, with 35 members...

. It was named in honor of Thomas Jefferson

Thomas Jefferson

Thomas Jefferson was the principal author of the United States Declaration of Independence and the Statute of Virginia for Religious Freedom , the third President of the United States and founder of the University of Virginia...

. The county is located in the north-central portion of the state, on the southmost edge of the Appalachian Mountains

Appalachian Mountains

The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...

, in the center of the (former) iron

Iron

Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

, coal

Coal

Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

, and limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 mining

Mining

Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

 belt of the Southern United States

Southern United States

The Southern United States—commonly referred to as the American South, Dixie, or simply the South—constitutes a large distinctive area in the southeastern and south-central United States...

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