Although it was a slave state, Maryland remained in the Union during the American Civil War, and its proximity to Washington D.C. and Virginia made it a significant strategic location.

As of 2015[update], Maryland had the highest median household income of any state, owing in large part to its proximity to Washington, D.C., and a highly diversified economy spanning manufacturing, retail services, public administration, real estate, higher education, information technology, defense contracting, health care, and biotechnology.

Sixteen of Maryland's twenty-three counties, and the city of Baltimore, border the tidal waters of the Chesapeake Bay estuary and its many tributaries,[20][12] which combined total more than 4,000 miles of shoreline.

[35] As the flow of indentured laborers to the colony decreased with improving economic conditions in England, planters in Maryland imported thousands more slaves and racial caste lines hardened.

In December 1790, prior to the move of the national capital from Philadelphia in 1800, Maryland donated land selected by first President George Washington to the federal government for its creation.

[36] Governor Thomas Holliday Hicks suspended the state legislature, and to help ensure the election of a new pro-union governor and legislature, President Abraham Lincoln had a number of its pro-slavery politicians arrested, including the Mayor of Baltimore, George William Brown; suspended several civil liberties, including habeas corpus; and ordered artillery placed on Federal Hill overlooking Baltimore.

[44] Whites did impose racial segregation in public facilities and Jim Crow laws, which effectively lasted until the passage of federal civil rights legislation in the mid-1960s.

Baltimore grew significantly during the Industrial Revolution, due in large part to its seaport and good railroad connections, attracting European immigrant labor.

In 1902, the state regulated conditions in mines; outlawed child laborers under the age of 12; mandated compulsory school attendance; and enacted the nation's first workers' compensation law.

[51] It ranges from sandy dunes dotted with seagrass in the east, to low marshlands teeming with wildlife and large bald cypress near the Chesapeake Bay, to gently rolling hills of oak forests in the Piedmont Region, and pine groves in the Maryland mountains to the west.

The highest point in Maryland, with an elevation of 3,360 feet (1,020 m), is Hoye Crest on Backbone Mountain, in the southwest corner of Garrett County, near the border with West Virginia, and near the headwaters of the North Branch of the Potomac River.

Close to the small town of Hancock, in western Maryland, about two-thirds of the way across the state, less than 2 miles (3.2 km) separates its borders,[52] the Mason–Dixon line to the north, and the northwards-arching Potomac River to the south.

[71] Every year during the last week of July, they are captured and swim across a shallow bay for sale at Chincoteague, Virginia, a conservation technique which ensures the tiny island is not overrun by the horses.

[66] The Piedmont region, which includes northern and western greater Baltimore, Westminster, Gaithersburg, Frederick, and Hagerstown, has average seasonal snowfall totals generally exceeding 20 inches (51 cm), and, as part of USDA Hardiness zones 7b and 7a,[66] temperatures below 10 °F (−12 °C) are less rare.

[82] Because of its location near the Atlantic Coast, Maryland is somewhat vulnerable to tropical cyclones, although the Delmarva Peninsula and the outer banks of North Carolina provide a large buffer, such that strikes from major hurricanes (category 3 or above) occur infrequently.

Southern Maryland is still somewhat rural, but suburbanization from Washington, D.C., has encroached significantly since the 1960s; important local population centers include Lexington Park, Prince Frederick, California, and Waldorf.

Other languages with a large number of speakers in Maryland include Vietnamese (0.4%), Russian (0.4%), Hindi (0.3%), Urdu (0.3%), Persian (0.3%), Nepali (0.3%), Haitian Creole (0.2%), and Telugu (0.2%).

[132] Maryland's multiculturalism and diversity can be explained by its historically large African American population, and immigration brought by the importance of the D.C. and Baltimore areas, especially from Central America, Africa, the Caribbean, and Asia.

As a former slave state, Maryland has had a large African-American population for much of its history; African American populations have increased over time with the Great Migration to the D.C. and Baltimore areas, and in more recent times with the New Great Migration and with movement out from Washington D.C. into Montgomery, Prince George's, and Charles counties, as a result of gentrification and rising housing costs in D.C. causing many African Americans to leave.

[161] In May 2012, Maryland's Court of Appeals ruled that the state will recognize marriages of same-sex couples who married out-of-state, no matter the outcome of the November election.

The once-mighty primary metals sub-sector, which once included what was then the largest steel factory in the world at Sparrows Point, still exists, but is pressed with foreign competition, bankruptcies, and mergers.

[173] Although the port handles a wide variety of products, the most typical imports are raw materials and bulk commodities, such as iron ore, petroleum, sugar, and fertilizers, often distributed to the relatively close manufacturing centers of the inland Midwest via good overland transportation.

The southern counties of the western shoreline of Chesapeake Bay are warm enough to support a tobacco cash crop zone, which has existed since early Colonial times, but declined greatly after a state government buy-out in the 1990s.

[183] Maryland has experimented with healthcare payment reforms, notably beginning in the 1970s with an all-payer rate setting program regulated by the Health Services Cost Review Commission.

[186][187] Amtrak trains, including the high-speed Acela Express serve Penn Station in Baltimore, BWI Airport, New Carrollton, and Aberdeen along the Washington, D.C. to Boston Northeast Corridor.

The WMATA's Metrorail rapid transit and Metrobus local bus systems (the 2nd and 6th busiest in the nation of their respective modes) provide service in Montgomery and Prince George's counties and connect them to Washington D.C..

The MTA's Commuter Bus system provides express coach service on longer routes connecting Washington, D.C. and Baltimore to parts of Central and Southern MD as well as the Eastern Shore.

While Republicans typically win more counties in statewide elections by piling up large margins in the west and east, they are usually overcome by the densely populated and solidly Democratic Baltimore–Washington axis.

[203] In 2022, Wes Moore became the first Democrat elected Governor of Maryland since 2010, replacing Republican Larry Hogan, who did not run for re-election due to term limits.

Maryland's 24 public library systems deliver public education for everyone in the state of Maryland through a curriculum that comprises three pillars: Self-Directed Education (books and materials in all formats, e-resources), Research Assistance & Instruction (individualized research assistance, classes for students of all ages), and Instructive & Enlightening Experiences (e.g., Summer Reading Clubs, author events).