In the height of the Enlightenment, men influenced by the new political theories of the era launched two of the largest revolutions in history. These two conflicts, on two separate continents, were both initially successful in forming new forms of government. And yet, the two conflicts, though merely a decade apart, had radically different conclusions. How do two wars inspired by more or less the same ideals end up so completely different? Why was the American Revolution largely a success and the French Revolution largely a failure? Historians have pointed to myriad reasons—far too various to be listed here. However, the most frequently cited are worth mentioning. For one, the American Revolution was far removed from the Old World; that is, since it was on a different continent, other European nations did not attempt to interfere with it.
However, in the French Revolution, there were immediate cries for war from neighboring nations. Early on, for instance, the ousted king attempted to flee to neighboring Austria and the army waiting there. The newly formed French Republic also warred with Belgium, and a conflict with Britain loomed. Thus, the French had the burden not only of winning a revolution but also defending it from outside. The Americans simply had to win a revolution.
Secondly, the American Revolution seemed to have a better chance for success from the get-go, due to the fact that Americans already saw themselves as something other than British subjects. Thus, there was already a uniquely American character, so, there was not as loud a cry to preserve the British way of life. In France, several thousands of people still supported the king, largely because the king was seen as an essential part of French life. And when the king was first ousted and then killed, some believed that character itself was corrupted. Remember, the Americans did not oust a king or kill him—they merely separated from him.
Finally, there is a general agreement that the French were not as unified as the Americans, who, for the most part, put aside their political differences until after they had already formed a new nation. The French, despite their Tennis Court Oath, could not do so. Infighting led to inner turmoil, civil war, and eventually the Reign of Terror, in which political dissidents were executed in large numbers. Additionally, the French people themselves were not unified. The nation had so much stratification that it was impossible to unite all of them—the workers, the peasants, the middle-class, the nobles, the clergy—into one cause. And the attempts to do so under a new religion, the Divine Cult of Reason, certainly did not help. The Americans, remember, never attempted to change the society at large; rather, they merely attempted to change the government.