Christopher Randall, the first of his line in the province of Maryland, settled in Anne Arundel County in the year 1679. There he purchased three tracts of land totaling nearly 1,000 acres, and named them Randall's Fancy, Randall's Purchase, and Randall's Range. Another original land-grant name from that time, Soldier's Delight, still exists in Northwest Baltimore County. Christopher died in 1684, leaving behind his wife Johanna, and his sons Christopher Randall Jr. and Thomas Randall. The family later moved to Northwest Baltimore County (ca. 1719), where the area known as Randallstown preserves their name. According to the 1877 Atlas of Baltimore County, Randallstown was situated seven miles from Baltimore City. Christopher and Thomas opened a tavern on a dirt toll road, which would eventually become Liberty Pike.

The Old Court Road was originally an old Indian trail, then used by rangers from Fort Garrison to keep Susquehannock and Shawnee Indian incursions in check. These two tribes of Indians were occasionally hostile to white settlers, prompting the construction of Fort Frederick in the 1750's to protect settlers along the Cumberland Road. Fort Garrison was built in 1695, and is still standing, though surrounded by a housing development. It is a small stone blockhouse, but easily defensible against arrows, spears and axes. The Old Court Road was later used as the road to the county court at Joppatown, the county seat of Baltimore County from 1712 to 1768 and the rival of Baltimore City. Because of the heavily wooded nature of the surrounding land, the area became known as Garrison Forest.

There were 11,379 households out of which 34.3% had children under the age of 18 living with them, 50.0% were married couples living together, 17.6% had a female householder with no husband present, and 28.4% were non-families. 23.8% 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 2.65 and the average family size was 3.13.

In the CDP the population was spread out with 26.3% under the age of 18, 7.0% from 18 to 24, 30.2% from 25 to 44, 24.8% from 45 to 64, and 11.6% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 84.1 males. For every 100 females age 18 and over, there were 79.0 males.

The median income for a household in the CDP was $58,686, and the median income for a family was $66,089. Males had a median income of $39,455 versus $36,020 for females. The per capita income for the CDP was $24,059. About 4.2% of families and 5.5% of the population were below the poverty line, including 5.9% of those under age 18 and 5.3% of those age 65 or over.