Question

What militia group prevented general burgoynes army from capturing supplies from an American supply base at bennington,Vermont

Answer 1

The militias that prevented it were the Green Mountain Boys were a Vermont military unit.

In Greening's Battle of Bennington, the Green Mountain Boys helped US forces defeat an army detachment of British General John Burgoyne led by Lieutenant Colonel Friedrich Baum.

Answer 2

The militia group that prevented general Burgoyne's army from capturing supplies from an American supply base at Bennington, Vermont is :
The Green Mountain Boys
They later captured Fort Ticonderoga, which was the first victory for American army in the war

hope this helps