The most successful crusades were the first four, however there were numerous crusades following the first four. In fact, the Crusades went on until approximately 1300. The later crusades were not at all successful. The decline of the papacy also brought the decline of the European unity and power. This separation of the European powers was a great reason why the later crusades were unsuccessful. (source) (source)

To start, the Children’s Crusade was a complete failure. Despite the name there were not many children going on this crusade, in fact they used this name to refer to adults that had not yet grown up. However, to this day the legend is that thousands of young children under the age of 12 went on a crusade to try and recover the Holy Land. These adults did not at all succeed in completing their mission. On there was to the Holy Land they dropped off like flies. Many of those that traveled by boat were shipwrecked and died, the other crusaders that traveled by boat were taken to North Africa, were they were sold into slavery. Those on foot, settled on their way to the Holy Land. (source) (source)

The fifth and six crusades cam after this, but were no more helpful in taking back Jerusalem. The fifth crusade took 10 years to complete and still they did not have any different result in their efforts. At the start the main expeditions were to Egypt. Frederick II then made efforts to the Holy Land and succeeded in a treaty; however after being excommunicated he lost Jerusalem again, in 1244. The sixth crusade did not turnout much better; Frederick made very good efforts that led no where. By this time, the decline of the papacy’s power was evident. Part of the reason why the crusades kept becoming less successful was because only one power would go and fight, Europe was no longer united under the crusades. (source) (source) (source) (source, Google Books)

The seventh crusade was called the shepherd’s crusade and was an effort by Louis IX of France. This failed when he was captured in Egypt, after problems were caused by the Knights Templar. However the peasant movement still went on after their leader was captured. After causing many troubles however, the crusaders were excommunicated. The 8th crusade was again led by Louis IX of France, however this effort was much better organized than the last. Despite their better efforts, there were again defeated in Mansura, right were the crusaders had been defeated in the fifth crusade. The ninth crusade which ended all the others was deemed a complete failure on the efforts against the Baibars. (source) (source) (source, Google Books) (source, Google Books)

After this, the Crusaders and Europeans were attacked ruthlessly. The Middle Eastern people massacred many of their big cities killing all those that could not leave in time. The Crusaders were unable to fight back. The Crusades, if anything only slightly delayed the efforts of the Muslims. Of the numerous efforts by the crusaders, only one or two were “successful” and you can see through the numerous failures that the last crusades were not deemed “successful”. (source) (source)