This video is really good to watch if you are studying about American Revolution.
The Green Mountain Boys were a militia organization which was first established in 1760s. The Green Mountain Boys were created in southwestern Vermont, and were made up of men from Vermont, Massachusetts, and Connecticut that held land titles from New Hampshire that entitled them land between Lake Champlain and the Connecticut River, which is modern day Vermont. However, the British crown gave all of that land to New York, and ignored the New Hampshire land grants. The group gathered and joined together to keep New York settlers out of Vermont, and keep all the land for people with New Hampshire titles. They drew their name from the Green Mountains of Vermont.
Click this link for The American Revolution Timeline: http://www.timetoast.com/timelines/the-american-revolution-timeline--24