Founding year: the first Monrovia post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives Monrovia’s History grade
On its age, its old homes and the National Register, Monrovia is more historic than 25% of U.S. towns, #158 of 261 in Maryland. Its age holds the grade up; its share of homes from before 1940 pulls it down.
C−
HistoryA character grade: shown, never part of Monrovia’s overall grade.
Few Maryland towns list much on the Register (a typical Maryland town has 0.9 per 10,000 residents, the U.S. 2.4), so Monrovia’s 0.0 sits below most of its state (20% of Maryland towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from D− to C+. The pre-1940 share (±1.3 points) is firm at this size. The founding year is the first post office, not a stated founding date.
Founding year: the first post office (other dates in Quick answers). Homes: Census ACS 2020–24. National Register: National Park Service, May 2026 list; each listing counted once (boundary changes and added documentation belong to their listing), and a historic district counts its contributing buildings. How TownRatings grades history →
What stands out about Monrovia’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
In 1831, Monrovia became a station on the Baltimore and Ohio Railroad and provided service to the mills and access for travelers to New Market, MD. A watering station for the trains was built later in 1840. Monrovia was impacted by the Civil War with the Monrovia General Store, used as a dry goods store from the mid-nineteenth century until the early twentieth century, being sacked by Confederate troops after the Battle of Monocacy. During the Civil War, Monrovia also made the front page of the September 16, 1862 issue of The New York Herald:
The Monrovia post office opened in 1833, the earliest record of the town by name (U.S. post office records).
How does Monrovia rank for history?
Monrovia is more historic than 25% of U.S. towns, #158 of 261 in Maryland. The History grade combines the town’s founding era, the share of homes built before 1940 and its National Register listings. It’s a character grade, so it isn’t part of the overall grade. How it works.
How old are the homes in Monrovia?
0.0% of Monrovia’s homes were built before 1940 (Census estimate, ±1.3 points), against a typical 3.3% for a Maryland town; the median home was built in 2015.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021).
From Wikimedia Commons (8), Wikipedia, Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, the US Post Offices dataset (Blevins & Helbock) and the USGS Geographic Names Information System. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
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