Final answer:
Colonial men joined the American Army due to a tradition of militia service, desire for independence, and in some cases, slaves and free blacks saw it as a pathway to freedom. They faced many obstacles, such as lack of supplies and unity, but were united by the common cause of American freedom.
Step-by-step explanation:
Colonial men joined the American Army for a variety of reasons during the Revolution. Some, like the Minutemen, were part of an established militia tradition and were driven by a sense of duty and the call to protect their liberties against British rule. Northern slaves and free blacks saw military service as a path to personal freedom and were inspired by the promise of the Declaration of Independence, with over 5,000 ultimately serving in the Continental Army.
Despite being constantly challenged by lack of manpower, organizational difficulties, and equipment shortages, these colonial forces, comprised of common farmers, shopkeepers, and even individuals of differing racial backgrounds, all united under the common cause of American freedom.
Facing the reality of Britain's encroachment, Indians sought to preserve their lands by aligning with the British, whereas many slaves found British offers of emancipation compelling enough to join them, particularly evidenced by Lord Dunmore's proclamation.