In fact, Robert Lee had initially wanted, like Winfield Scott, to fight a field encounter battle against the British Army.
The reason was simple: Harrisburg had more than twenty thousand defenders, along with over four thousand temporarily recruited volunteers.
It was his first time commanding an army of such scale. Looking at the endless ranks stretching before him, he could not help but feel heroic ambition swell within his chest. He unconsciously wanted to show what he was capable of.
Most importantly, the British Army had grown so arrogant after one victory after another that its vanguard had become separated from the bulk of its rear forces.
The British vanguard numbered only a little over five thousand men and lacked heavy weapons such as artillery.
The British Army had marched a long way to fight, while the US Army waited at ease for the exhausted enemy. Robert Lee could hardly find a reason to lose.
So he prepared to move his troops and catch the British off guard, only for Robert Lee to quickly discover a problem.
The officers under his command simply could not control an army of this size. Forget fighting—they even had trouble marching.
Taking into account Winfield Scott's disastrous defeat in New York, Robert Lee decisively chose to fall back and defend Harrisburg. At the same time, he evacuated the civilians, including those volunteers, leaving behind only federal soldiers and government officials.
Those volunteers had no idea what war was. They were nothing more than a pack of drunken cowboys and drifters.
If a real fight broke out, they would likely be the first to surrender, and their panic would infect the other soldiers as well.
Rather than keep such an unstable danger at his side, it was better to have them escort the civilians away.