What is the immediate effect of the French Revolution, and what is the long-term effect of this revolution?
The immediate impact of the French Revolution was the death of thousands of aristocrats on the guillotine, the desecration of many Catholic cathedrals and churches and the abolishment of religion, and the establishment of a republic in 1792 after the arrest of the King at the Royal Palais. Then, the legislative power of the republic fell to the National Convention. But, in 1793, the Jacobins seized power and unleashed the Reign of Terror (1793-1794) with nearly 1200 people meeting death on the guillotine.
In 1794 the French people revolted against the excesses of the Reign of Terror. After this a plebiscite ratified a constitution and took effect in 1795, installing what is known as the Directory. Because this group met with opposition from the remaining Jacobins, Napoleon Bonaparte was able to gain power and organize the coup which installed the Consulate. In 1804, Bonaparte established himself as Emperor, a position which effectively did away with the specifically republican phase of the French Revolution.
With the monarchy restored after Bonaparte's exile in 1814, albeit only 100 days, France was still not a democracy. But by the revolution of 1848, and the establishment of the Second Republic whose motto was Liberte, Equalite, Fraternite, there began a more democratic trend in government with the promulgation of universal suffrage. However, there was yet support for the monarchists, with Napoleon III eventually being made monarch in 1852. Conflict between the two ideologies existed until 1879.
With the establishment of democratic and socialist ideas in France, old ideas gave way as in the Haitain revolution of the slaves, who obtained liberty. The New Enlightenment, and secularism, separation of church and state, came into being. These were both movements toward modernization. Thus, the modern era came in the shadow of the French Revolution.
I think that you will experience different answers to this question. In my mind, the immediate effect of the French Revolution was the dissolution of the French Royal Monarchy and the forcible removal of it from French government. At its singular instant, the obliteration of the French noble rule would have to be one of the most pressing and immediate effects. In long term scope, I would say that the Revolution ended up proving the vast difference between declaring independence and maintaining it. The entropy of the French Revolution from a moment for liberty, fraternity, and equality and into one where the Reign of Terror dominated, culminating in the rule of Napoleon showed how revolutions are not an automatic guarantee of freedom. The same spirit and vitality that inspires and causes change has to be harnessed into providing structure and guidance, which helps to make the American Revolution and its sustaining rule that followed all the more amazing from a historical point of view.
I'd say that the immediate impacts of the French Revolution were twofold. First, there was a huge impact on the way of life in France itself. The aristocracy was pretty much eliminated and France became a democratic country. This was a major change. Second, the revolution led to a series of wars as the French tried to export their revolution abroad.
In the long term, I would argue that the French Revolution and the American Revolution combined to really drive the idea of democratization. I think that they inspired other countries to become more democratic to the point where democracy became the more or less universal form of government in the rich world.