The name change is linked to a postal clerk who felt that the last three letters, "ugh", did not properly fit on the rubber stamps being used at the time.

By 1893, postal guides were referring to the town as Upper Marlboro, though it took several more decades for the new spelling to become widely accepted among residents.

Despite a proposed ballot to have it formally changed back in 1968, the new name stuck, and by 1971, the old spelling, while not completely vanquished, had become severely depreciated.

It is named after Colonel Henry Darnall, a wealthy Roman Catholic planter, who was the Proprietary Agent of Charles Calvert, 3rd Baron Baltimore and who served for a time as Deputy Governor of the Province.

The house itself was built c. 1742 by a merchant named James Wardrop, after he bought some of the land from Eleanor Darnall Carroll and her husband.

County surveyor Thomas Truman Greenfield conducted a survey of 100 acres (0.40 km2) of the three estates from which the town would be formed.

[8] Residents of the area were not happy with Greenfield's initial layout and petitioned the General Assembly to have the town replatted.

In 1814, Upper Marlboro was seized by British forces under the command of Major-General Robert Ross and Rear Admiral George Cockburn during the campaign leading up to the Battle of Bladensburg and the Burning of Washington.

[9] During the late 18th and early 19th centuries, many prominent merchants, lawyers, and politicians lived and worked in the area.

In 1878, Michael Green, an African-American man accused of assaulting a white woman, was taken from the country jail and hanged from a tree outside of town.

It initially boomed as a port town for tobacco trade, but the clearing and cultivation of land for farming would lead to erosion in the area.

The fields of tobacco that once dominated the area have been converted over to residential developments, with the number of farms dwindling each year.

According to county historian Susan Pearl, "They wanted the neo-classic Georgian university campus building, and that's what they got."

[15] In January 2007, the courthouse briefly caught fire again when sparks from a construction worker's welding tool ignited building materials on the roof.

[16] On March 12, 2009, the Duvall Wing of the Prince George's County Courthouse reopened after being closed in 2001 for renovations.

[17] Since the 1990s, the Prince George's County government has been purchasing land in Largo, Maryland, due to its convenient location near the Washington Metro and interstate highways.

The northern terminus of the Stephanie Roper Highway Archived December 24, 2014, at the Wayback Machine (Maryland Route 4) is in Upper Marlboro at the intersection of Pennsylvania Avenue and Water Street.

Major features of the town include the courthouse, jail, county office building, board of education, and a lake with a walking path.

This arena is used for events such as hockey games, circuses, rodeos, conventions, trade shows, and graduation ceremonies of many regional high schools, as well as daily overflow parking for county governmental employees, jurors, and visitors.

Although the surrounding area has many rural, pastoral features, including horse farms, housing developments are increasingly prevalent.

Greater Upper Marlboro has a population of nearly 20,000 in an area of 77 square miles (200 km2), as designated by the post office.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters.

Its flow starts in Woodmore, Maryland, and enters the Patuxent River just a few miles south of Upper Marlboro.

As of 2015[update] about 6,000 people work in the town, with employees of the Prince George's County government making up the majority.

Upper Marlboro's economy consists of small businesses, with a majority of employment opportunities in the city in the courthouse.

[39] Wise High, located in the Westphalia census-designated place near Upper Marlboro,[40][41] opened in 2006.

[46] Public schools in the nearby area include: Private schools in the nearby area include: Upper Marlboro is served by the Upper Marlboro Branch of the Prince George's County Memorial Library System.

[49] From 1923 to 1935, Black students attended Marlboro Colored High School in Upper Marboro.

[48] The Chesapeake Icebreakers of the East Coast Hockey League played two seasons in Upper Marlboro from 1997 to 1999 at The Show Place Arena, just outside town, before moving to Jackson, Mississippi.

The Chesapeake Tide of the Continental Indoor Football League started play at The Show Place Arena, just outside town, in 2007.