Gen. Washington "did not utter a word for half an hour"

On 5 Aug 1775, Gen. John Sullivan, a former delegate to the Continental Congress from New Hampshire (shown here), sent an urgent letter to that body about a supply crisis its army had suddenly become aware of:

General [George] Washington has, I presume, already written you on the subjects of this letter. We all rely upon your keeping both the contents of his letter and mine a profound secret.

We had a general council the day before yesterday, and, to our great surprise, discovered that we had not powder enough to furnish half a pound a man, exclusive of what the people have in their horns and cartridge-boxes.

This situation we are reduced to by the Massachusetts Committee [of Safety?] making a return to General Washington of four hundred and eighty-five casks on his arrival, which he supposed were then on hand. To his surprise, he found that it was what was provided last winter, and that there is now on hand but thirty-eight barrels; which, with all the powder in the other magazines, will not furnish have a pound per man.

The General was so struck, that he did not utter a word for half an hour. Every one else was also astounded.

Sullivan asked all other colonies to send their gunpowder supplies to the army around Boston, saying, “Should this matter take air before a supply arrives, our army is ruined.” In other words, if the British military were to learn how little gunpowder the American troops had, they might well try to break through the siege lines and scatter the provincial forces.