Answer :

The Battle of Trenton was so important because the Continental army was in need of some encouragement/victory. General Washington realized that by the end of winter, many of the soldiers enlistments/duty would be done and many would go home thus, the army would be heavily reduced. So General George Washington planned and executed an attack on the British and British elite mercenaries, the Hessians in Trenton. Because it was winter, the British let down their guard and relaxed for the winter as was the tradition of the army to settle down in the winter. So an attack led by George Washington was launched. It required the colonist to cross the ice cold Delaware river, deep inside British held territory and into the British camp. The attack was a complete success. In the attack, the British/Hessians were defeated and about 1,000 of them were captured if I remember correctly. This daring successful attack on the British elite troops brought confidence and much needed encouragement tot he colonist. Which resulted in many of them staying in the army to continue fighting.