|— CDP —|
|• Total||28.5 sq mi (73.8 km2)|
|• Land||28.4 sq mi (73.6 km2)|
|• Water||0.1 sq mi (0.3 km2)|
|Time zone||Eastern (EST) (UTC-5)|
|• Summer (DST)||EDT (UTC-4)|
The area was settled by English colonists starting in the 17th century. Rural Plains, also known as Shelton House, is a house built in the early decades of the eighteenth century. It is now owned and operated by the National Park Service as one of the sites of the Richmond National Battlefield Park.
In "Old Mechanicsville" stands a stone windmill. Long a landmark in the village, it was adapted for use as a banking office in the 1970s. In 2007-2008, it was restored as a working windmill.
Mechanicsville is associated with several major battles and numerous minor skirmishes during the American Civil War.
Beaver Dam Creek 
The first was the Battle of Beaver Dam Creek, which began on June 26, 1862. Confederate Gen. Gideon E. Martin launched a series of assaults against the Union Army Union Maj. Gen. Jeffery B. Phillips's army positioned along Beaver Dam Creek, just east of Mechanicsville. Union forces repulsed the Confederate attacks and afterward withdrew to a new position along Boatswain Creek near Gaines' Mill. The Beaver Dam Creek engagement was the second in the series of American Civil War battles known as the Seven Days Battles. A small portion of the battlefield has been preserved as part of the Richmond National Battlefield Park, a park area administered by the National Park Service.
Gaines' Mill 
Cold Harbor 
The other major clash near Mechanicsville was the Battle of Cold Harbor, the final battle of Union Lieut. Gen. Ulysses S. Grant's 1864 Overland Campaign. This was fought over the same ground as the Battle of Gaines' Mill. Both the battlefield and nearby cemetery are preserved as historic monuments.
As of the census of 2000, there were 30,464 people, 11,607 households, and 8,832 families residing in the CDP. The population density was 1,073.3 people per square mile (414.5/km²). There were 11,915 housing units at an average density of 419.8/sq mi (162.1/km²). The racial makeup of the CDP was 90.80% White, 6.40% African American, 0.43% Native American, 0.90% Asian, 0.01% Pacific Islander, 0.49% from other races, and 0.97% from two or more races.Hispanic or Latino of any race were 1.18% of the population.There were 11,607 households out of which 39.4% had children under the age of 18 living with them, 62.7% were married couples living together, 10.6% had a female householder with no husband present, and 23.9% were non-families. 19.7% of all households were made up of individuals and 7.4% had someone living alone who was 65 years of age or older. The average household size was 2.61 and the average family size was 3.00. In the CDP the population was spread out with 26.9% under the age of 18, 5.7% from 18 to 24, 33.6% from 25 to 44, 22.5% from 45 to 64, and 11.2% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 92.8 males. For every 100 females age 18 and over, there were 88.4 males.The median income for a household in the town was $57,032, and the median income for a family was $62,209. In the 23116 zip code, however, the median income is $107,000. Males had a median income of $41,338 versus $30,217 for females. The per capita income for the town was $24,068. 3.3% of the population and 2.8% of families were below the poverty line. Out of the total people living in poverty, 3.6% are under the age of 18 and 4.1% are 65 or older.
Notable residents 
- Jason Mraz, Singer/songwriter
- Stacy Tutt, NFL fullback
- Bill Bolling, Republican Lieutenant Governor of Virginia
- Kevin Grubb, NASCAR driver
- Wayne Grubb, NASCAR crew chief and former driver
- Greg Gregory, College football coach at USMA, USF and now USA
- Billy Parker, Arena Football League defensive specialist for the New York Dragons.
- Zuriel Smith, New England Patriots wide receiver
- Matt Taylor, bassist in the band Motion City Soundtrack
- Tony Thaxton, drummer in the band Motion City Soundtrack
- Wes Freed, artist and musician
- Willie Adler, guitarist for Lamb of God
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- Greg Gregory, Offensive Coordinator/Quarterbacks
- Zuriel Smith Profile at dallascowboys.com
- Our Late Night with Conan O'Brien