President-elect Abraham Lincoln arrives secretly in Washington, D.C., after the thwarting of an alleged assassination plot in Baltimore, Maryland.

Abraham Lincoln was the 16th president of the United States, serving from 1861 until his assassination in 1865. He led the United States through the American Civil War, defeating the Confederate States of America and playing a major role in the abolition of slavery.

The Baltimore Plot concerned alleged conspiracies in February 1861 to assassinate President-elect of the United States Abraham Lincoln during a whistle-stop tour en route to his inauguration. Allan Pinkerton, founder of the Pinkerton National Detective Agency, played a key role in managing Lincoln's security throughout the journey. Though scholars debate whether or not the threat was real, Lincoln and his advisors clearly believed that there was a threat and took actions to ensure his safe passage through Baltimore. He ultimately arrived secretly in Washington, D.C., on February 23, 1861.

Baltimore is the most populous city in the U.S. state of Maryland. It is the 30th-most populous U.S. city with a population of 585,708 at the 2020 census and estimated at 568,271 in 2024, while the Baltimore metropolitan area at 2.86 million residents is the 22nd-largest metropolitan area in the nation. The city is also part of the Washington–Baltimore combined statistical area, which had a population of 9.97 million in 2020. Baltimore was designated as an independent city by the Constitution of Maryland in 1851. Though not located under the jurisdiction of any county in the state, it forms part of the Central Maryland region together with the surrounding county that shares its name.

Maryland is a state in the Southern and Mid-Atlantic regions of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east, as well as with the Atlantic Ocean to its east, and the national capital and federal district of Washington, D.C. to the southwest. With a total area of 12,407 square miles (32,130 km²), Maryland is the ninth-smallest state by land area, and its population of 6,177,224 ranks it the 18th-most populous state and the fifth-most densely populated. Maryland's capital city is Annapolis, and the state's most populous city is Baltimore.