Editing Macadam (section)

{{Short description|Road building method by John Loudon McAdam}}
{{Other uses|McAdam (disambiguation){{!}}McAdam}}
{{Lead too short|date=November 2023}}
{{Use dmy dates|date=April 2022}}
[[File:Rakeman – First American Macadam Road.jpg|thumb|An illustration of the first macadamized road in the United States between [[Boonsboro, Maryland|Boonsboro]] and [[Hagerstown, Maryland|Hagerstown]] in [[Maryland]] in 1823; in the foreground, workers are breaking stones "so as not to exceed {{convert|6|oz|g|-1|disp=sqbr}} in weight or to pass a {{convert|2|in|cm|0|spell=in|adj=on|disp=sqbr}} ring".]]
'''Macadam''' is a type of [[road]] construction pioneered by Scottish engineer [[John Loudon McAdam]] {{Circa|1820}}, in which [[crushed stone]] is placed in shallow, convex layers and compacted thoroughly. A binding layer of stone dust (crushed stone from the original material) may form; it may also, after rolling, be covered with a cement or [[bituminous]] binder to keep dust and stones together. The method simplified what had been considered state-of-the-art at that point.