Maryland created its last Eastern Shore county on August 17, 1867. The General Assembly carved Wicomico out of the northern portion of Somerset County and the western portion of Worcester County, partly to give the booming railroad town of Salisbury its own seat of government. Salisbury had been growing fast as a Pennsylvania Railroad stop on the Wilmington-to-Cape Charles trunk line, and the surrounding farmers needed a courthouse closer than the old county seats at Princess Anne or Snow Hill. Wicomico was the twenty-second county Maryland created; only Garrett County, established in 1872 in the far western mountains, came later. The new county got a charter form of government in 1964 and moved to an elected county executive system in 2006. A 2024 ballot measure to abolish the county executive position and revert to council-manager government was defeated by voters - a small civic detail that reveals how unsettled the lower shore's local governance still is, even 158 years in.

Wicomico County's northern boundary follows two of the most famous surveyed lines in American history. The county shares a border with Sussex County, Delaware. Part of that border is the Mason-Dixon Line, the boundary between Maryland and Delaware-Pennsylvania surveyed by Charles Mason and Jeremiah Dixon between 1763 and 1767. Part is the Transpeninsular Line, the east-west boundary across the Delmarva Peninsula that Mason and Dixon also helped fix. The two lines meet at a point about eight miles northwest of Salisbury - a stone marker in a small clearing that almost no one visits. That midpoint is one of the most important geographic landmarks of the colonial Mid-Atlantic, the spot from which the entire Mason-Dixon Line was effectively oriented. It is also the origin of a piece of American cultural shorthand: the line between North and South, between free and slave, between Pennsylvania and Maryland. The actual marker is a modest, weathered granite block. Most of the cars that pass it on Maryland Route 54 never slow down.

Perdue Farms is headquartered in Salisbury and is the largest employer headquartered in Wicomico County, with nearly 22,000 employees nationwide. The company was founded by Arthur W. Perdue in 1920 with fifty laying hens behind his Salisbury home. By 1971, when his son Frank Perdue went on television with the slogan 'It takes a tough man to make a tender chicken,' Perdue Farms was selling chicken nationally and Salisbury had become the brand's home. The Eastern Shore's poultry industry feeds urban America with billions of pounds of chicken a year, and the environmental footprint of that industry shows up in the nutrient runoff that has plagued the Chesapeake Bay for decades. Wicomico County is, on any given afternoon, more chicken farms than human settlements - rows of long white grow-out houses spaced across the corn and soybean fields, with the processing plants and rendering facilities consolidated near the city. The poultry industry replaced a vanished truck-farming economy after California's Central Valley took over fresh-produce markets in the 1950s and 1960s.

Piedmont Airlines, the regional carrier that operates as American Eagle on behalf of American Airlines, is headquartered at the Salisbury-Ocean City-Wicomico Regional Airport. The original Piedmont was founded in 1948 in Winston-Salem and merged into US Airways in 1989; the current Piedmont, founded as Henson Airlines in 1962 by Maryland aviation pioneer Richard A. Henson, took the Piedmont name in 1993. Henson, who grew up in Hagerstown, made his fortune in test piloting and aircraft manufacturing before founding the airline that now puts nearly 400 flights a day across the East Coast. The airport bears the names of three communities - Salisbury, Ocean City, and Wicomico - because it serves all of the Lower Shore, including the summer beach traffic. It runs daily American Eagle flights to Philadelphia and Charlotte. From the air, the airport's location is unusual: a working regional carrier headquarters and crew base sits surrounded by chicken farms.

The 103,588 residents Wicomico County recorded in the 2020 census make it the largest county on Maryland's Lower Shore by population. Salisbury, the county seat, is the largest city. The county's media economy reflects its centrality: most of the Delmarva television market's major-network affiliates broadcast from Salisbury studios. WBOC-TV carries CBS, Telemundo, NBC, and Fox subchannels; WMDT carries ABC and The CW; the Maryland Public Television affiliate WCPB carries PBS. For the entire peninsula - parts of Maryland, Delaware, and Virginia - the evening news comes out of a building on Radio Lane in Salisbury. The Daily Times, the regional newspaper of record, also publishes from Salisbury. A small county that for most of its history was a railroad stop in a farming district is now the media capital of a three-state peninsula. The places where houses get built, in the end, also become the places where the broadcasts go out.