Effingham was among the original counties of the state of Georgia, created February 5, 1777, during the American Revolution from the colonial parishes of St. Matthew and St.

[3] Its name honors Lord Effingham, an English champion of colonial rights, who resigned his commission rather than fight against the rebel colonists during the American Revolution.

After the war, notable Georgia patriots including Lyman Hall, Samuel Elbert, Edward Telfair, George Walton and Stephen Heard all made direct appeals to the Loyalists of Effingham County to "stay on" in Georgia, under the new republican form of government.

It was established in 1918 at the site of the former Savannah Atlanta Railroad Locomotive Repair Shop in Springfield.

In 2007 it became the site of EFACEC Group, a Portuguese-based transformer manufacturer for their North and Central America operations.

The U.S. factory is located in Rincon, Georgia and produces both core and shell technology power transformers.

Other businesses include the Flint River Services refrigerated storage, ValuePart distribution center, as well as expansions of several existing industries in the park.

A potential of 10,000,000 square feet (930,000 m2) of light manufacturing and/or Distribution Center/ Warehousing space exists at this site.

Industry in Effingham County includes paper manufacturing—Georgia Pacific (Savannah River Mill), high-precision turbine blade production—Doncasters, aluminum geodesic dome production—Temcor, concrete pipe manufacturing—Hanson, customized business jet interiors—Edward's Interiors, electrical distribution power transformer production—EFACEC PT, among many others.

After supporting Dixiecrat Strom Thurmond in 1948, it began voting Republican earlier than most Georgia counties, albeit by very narrow margins.

The only Democratic Party candidate to win the county since 1944 was Jimmy Carter, who won it convincingly in his statewide landslide in 1976 and narrowly in 1980.