Question

Which answer best describes John McAdam's role in the history of transportation in America?

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.

Answer 1

The best answer to describe John McAdam's role in the history of transportation in America is : McAdam invented a method to build stone roads. 
Back then, the method is called 'Mcadamisation' , using various of mixed materials to build a smooth hard surfaces

Answer 2

it is b: McAdam invented a method to build stone roads.

hope this helps!