A Maryland historical marker stands at the entrance to the Holy Trinity Church and Lower School Campus grounds. The church stands at the site of "Henderson's Chapel" that was completed in 1712 by the Rev. Jacob Henderson.
Henderson's Chapel was deeded to the church in 1737 when Rev. Henderson sold the land called "Bel Air" to Governor Samuel Ogle and Colonel Benjamin Tasker. The present church building dates from 1836.
The Parish Hall, which is the oldest section of the Lower School building, was built in 1961. The Day School was originally established in 1963 as a preschool.
Through continued expansion over the years, the school has grown steadily and now includes the Daisey Lane campus that opened in 1999. As a preschool through eighth grade school, Holy Trinity Episcopal Day School has the capacity to serve 622 students.
The Lower School Campus serves grades one through four, and the Daisey Lane Campus serves the Preschool, Kindergarten, and grades five through eight.
