Figure 4:8th Massachusetts Cookhouse, Elkridge Heights, June 1861. Maryland State Archives.
Figure 5:Stereograph shows Cook's Boston Light Artillery overlooking the Thomas Viaduct at Camp Essex, near Relay House in Elkridge, Maryland. Library of Congress Control Number 2011648034.
Figure 6:Harper's Weekly, 5/25/1861
Figure 7:“The famous Relay House, on the Baltimore & Ohio R. R.” (Courtesy of National Museum of American History)
Figure 8:Commissary department. Encampment of the Mass. 6th Regiment of Volunteers at the Relay House near Baltimore, Md., 1861 Digital ID: (digital file from b&w film copy neg.) cph 3a04036 http://hdl.loc.gov/loc.pnp/cph.3a04036