Except from the recommended edition:

It is not chance that rules the world. Ask the Romans, who had a continuous sequence of successes when they were guided by a certain plan, and an uninterrupted sequence of reverses when they followed another. There are general causes, moral and physical, which act in every monarchy, elevating it, maintaining it, or hurling it to the ground. All accidents are controlled by these causes. And if the chance of one battle—that is, a particular cause—has brought a state to ruin, some general cause made it necessary for that state to perish from a single battle. In a word, the main trend draws with it all particular accidents.

Online:
Online Library of Liberty (Free version)
Amazon (Recommended edition)