Final answer:
The colonial militias and the modern U.S. Army differ in terms of composition, equipment, and scale of operations.
Step-by-step explanation:
The colonial militias and the modern U.S. Army differ in several ways.
Firstly, the colonial militias were composed of able-bodied men in each colony who were responsible for providing and caring for their own weapons. On the other hand, the modern U.S. Army is a professional military force with standardized equipment and a hierarchical command structure.
Secondly, the colonial militias were more of a local defense force, called upon to assemble at a moment's notice. In contrast, the modern U.S. Army operates on a much larger scale and is trained to engage in combat operations around the world.