Rockville began when Owen's Ordinary, an inn and tavern, was established in this area around 1750. It functioned as the seat of lower Frederick County and in 1776 became the seat of Montgomery County when it was created. In 1784, William P. Williams subdivided 45 acres of his land into building lots and called it "Williamsburgh." Fifteen years later, structures had been built on 38 lots. The Williamsburgh plat had legal problems and in November 1801, the Maryland General Assembly directed that the lots be resurveyed and a town erected "to be called Rockville." The town plan was recorded in 1803.
This boundary stone, with the letters "B.R." incised, marks the "Beginning of Rockville" shown in the lower right of the plan at the southeast corner of Block I, lot 1. The plan has a grid pattern of six streets, 19 blocks, and a total of 85 lots. The Court House lot fits into the notch on the right border in Block VIII.
For many years, the boundary stone was neglected, half-buried in the weeds of an undeveloped lot. It resurfaced when the Rockville Library was built in the 1950s. It was placed near its original location in 1961 where it serves as an everyday reminder of the modest beginnings of Rockville.