Which answer best describes john mcadam's role in the history of transportation in america? (5 points)

mcadam invented the first steamboat.
mcadam invented a method to build stone roads.
mcadams's steam engine was used to build roads.
mcadam's steam engine powered the first locomotive.

The correct answer is the second one, McAdam invented a method to build stone roads.

McAdam was appointed surveyor to the Bristol Turnpike Trust in 1816 and decided to remake the roads he was supervising, applying his own original construction method which later became known as macadamisation 

You don’t have to names or other options up here so idk dude