United States Department of Transportation - Federal Highway Administration,
Painting by Carl Rakeman.
Macadam Road Construction, Maryland, 1823
The macadam road construction principle permitted the construction
of the first modern all-weather hard surface roads. The above painting
shows the process being applied to build the first macadam surface road
in the United States in 1823. It linked Hagerstown and Boonsboro, Maryland.
The road was composed of three layers of compacted rocks with the top
layer cemented with water to create a concrete like surface. Drainage
was insured by a curved road surface with runoff water accumulating
in side ditches.