How did the French Revolution impact other countries?
The French Revolution had a massive impact on the world. One of the more well known impacts is the domino effect of revolutions inspired by the French Revolution.
In Haiti, which at the time of the French Revolution was a French colony called Saint Domingue, independence movements broke out when the National Assembly passed the Declaration of the Rights of Man and the Citizen. If all men are free, could that include the enslaved Africans in the French colony of Saint Domingue? Initially, all men in Haiti were granted their freedom, until Napoleon's need to finance his wars in the early 19th century saw the reinstatement of slavery of Haiti. After a few years of fighting, the Haitians won their independence from France, a movement directly caused by the French Revolution. When Haiti became independent, revolutionary leaders in South America like Simon Bolivar were inspired to fight for independence in many South American colonies, and most achieved their independence by 1825.
In Europe, other nations that had similar social problems and political structures of revolutionary France staged similar liberal independence movements. Some countries who attempted revolution include Italy, Prussia, Austria, Germany, and France (again). These are called the revolutions of 1848 and were inspired by the French Revolution. The idea was that if the citizens of France could overthrow (and execute) their King, why can't the citizens of other European nations? While monarchs fought hard to suppress this thought, and in most cases won, it still shows how great an impact the French Revolution was on Europe.
After the French Revolution, Napoleon Bonaparte staged a coup d'etat and took control of France. During his reign as emperor, he expanded the French Empire across Europe, challenged British overseas territories, and ultimately bankrupted France. While his rule was not successful, and he was ultimately replaced by a King (negating all of the ideas laid out by the third estate in the French Revolution), he was a product of the French Revolution. The French Revolution's principles were spread throughout Europe because of Napoleon.
The French Revolution impacted other countries in various ways. In Europe, the revolution led to a series of wars between various countries and the French. It also led to the rise of Napoleon and the empire he won, albeit briefly.
Since you originally put this in the "United States of America" section, though, I will look mostly at the revolution's impact on the US. The French Revolution caused the US a great deal of trouble. First, it helped split the country between pro-British and pro-French factions. Second, it led to many problems in foreign policy. The French and British went to war, and the US was caught in between with both countries preying on US shipping to the other country. This eventually led to near-war with the French and finally to the War of 1812 with the British.
French liberation/occupation of almost all continental Europe provoked specially in Germany the birth of a national feeling, who gave later the unification of Italy, Germany, and after WW I Tchecoslovakia, Poland, Hungary, Yougoslavia unified under Serbian ruling etc.
Each one willing to become bigger, the fight was necessary and came with WW I.