The battalion was immediately formed and marched to the hall and went into camp. I was made Officer of the Day and posted pickets inside the yard, and all approaches to the camp."
Does this sound like an "invasion" to anyone? If it was an "invasion" they would have just taken anywhere they wanted to. 

Young continues, "Early in the evening the deputy marshal, dressed in citizen's clothing, called to see me with an apparently friendly message from the Queen's Marshall, Charles B. Wilson, but obviously to find out the disposition of our forces, and the part we proposed to take in the event of a fight. I understood his mission and extended to him a most cordial reception, took him all around the camp and emphatically informed him we were there simply to protect American life and property, and under no circumstances would we take part with either side.