structural:summarization
19th century

The city remained a part of surrounding Baltimore County and continued to serve as its county seat from 1768 to 1851, after which it became an independent city.

The Battle of Baltimore against the British in 1814 inspired the U.S. national anthem, " The Star-Spangled Banner ", and the construction of the Battle Monument, which became the city's official emblem. A distinctive local culture started to take shape, and a unique skyline peppered with churches and monuments developed. Baltimore acquired its moniker "The Monumental City" after an 1827 visit to Baltimore by President John Quincy Adams. At an evening function, Adams gave the following toast: "Baltimore: the Monumental City—May the days of her safety be as prosperous and happy, as the days of her dangers have been trying and triumphant."

Baltimore pioneered the use of gas lighting in 1816, and its population grew rapidly in the following decades, with concomitant development of culture and infrastructure. The construction of the federally funded National Road, which later became part of U.S. Route 40, and the private Baltimore and Ohio Railroad (B. & O.) made Baltimore a major shipping and manufacturing center by linking the city with major markets in the Midwest. By 1820 its population had reached 60,000, and its economy had shifted from its base in tobacco plantations to sawmilling, shipbuilding, and textile production. These industries benefited from war but successfully shifted into infrastructure development during peacetime.

Baltimore had one of the worst riots of the antebellum South in 1835, when bad investments led to the Baltimore bank riot. It was these riots that led to the city being nicknamed "Mobtown". Soon after the city created the world's first dental college, the Baltimore College of Dental Surgery, in 1840, and shared in the world's first telegraph line, between Baltimore and Washington, D.C., in 1844.

Maryland, a slave state with limited popular support for secession, especially in the three counties of Southern Maryland, remained part of the Union during the American Civil War, following the 55–12 vote by the Maryland General Assembly against secession. Later, the Union's strategic occupation of the city in 1861 ensured Maryland would not further consider secession. The Union's capital of Washington, D.C. was well-situated to impede Baltimore and Maryland's communication or commerce with the Confederacy. Baltimore experienced some of the first casualties of Civil War on April 19, 1861, when Union Army soldiers en route from President Street Station to Camden Yards clashed with a secessionist mob in the Pratt Street riot.

In the midst of the Long Depression that followed the Panic of 1873, the Baltimore and Ohio Railroad company attempted to lower its workers' wages, leading to strikes and riots in the city and beyond. Strikers clashed with the National Guard, leaving 10 dead and 25 wounded. The beginnings of settlement movement work in Baltimore were made early in 1893, when Rev. Edward A. Lawrence took up lodgings with his friend Frank Thompson, in one of the Winans tenements, the Lawrence House being established shortly thereafter at 814-816 West Lombard Street.