What led to the fall of the roman empire?

The were many reasons
1Invasions by Barbarian tribes

The most straightforward theory for Western Rome’s collapse pins the fall on a string of military losses sustained against outside forces

2Economic troubles and overreliance on slave labor

Even as Rome was under attack from outside forces, it was also crumbling from within thanks to a severe financial crisis

3The rise of the Eastern Empire

The fate of Western Rome was partially sealed in the late third century, when the Emperor Diocletian divided the Empire into two halves—the Western Empire seated in the city of Milan, and the Eastern Empire in Byzantium, later known as Constantinople.

4Weakening of the Roman legions

For most of its history, Rome’s military was the envy of the ancient world.

there were a lot more reasons as well but these are the main ones hope I helped

The answer is william henry harrison pursued and defeated british forces retreating into canada.