J. Crawford Neilson (1816 - 1900) was a noted Baltimore architect and was one of the founders of the Baltimore chapter of the American Institute of Architects.  In addition to the Main Building at Spring Grove, Mr. Neilson designed a number of notable buildings in Maryland and in neighboring states.  For example, he served as one of a series of principal architects who were responsible for the design of the South Carolina Statehouse in Columbia, SC.  He also designed the Hilltop Chapel at Green Mount Cemetery, and the Grace and St. Peter's Church (Park Avenue at Monument St.), both in Baltimore.