Here's a breakdown of his invention:
* Before Macadam: Roads were often muddy, dusty, and difficult to travel on.
* Macadam's innovation: He developed a method of using small, closely packed stones (instead of large, heavy stones) to create a strong and durable road surface.
* The key to his method: The small stones allowed for proper drainage, and the close packing created a solid, smooth surface.
Macadam's invention revolutionized road construction. His roads were cheaper and easier to build and maintain than traditional methods. They also allowed for faster and smoother travel.
In short, John Macadam is famous for making roads better, smoother, and more accessible for everyone.