There is absolutely no evidence that various Islamic Caliphates "visited America before Columbus".
Now of course Islamic civilization has been present in Morocco for 1300 years and the Iberian Caliphate was present in Southwest Europe for nearly 800 years. The Medieval Muslims of the greater Iberian peninsula, as well as Morocco would have known about the Atlantic Ocean, since it was their backyard-(certainly in the cases of Western Morocco, as well as the Portuguese coast). However, in all likelihood, the Atlantic Ocean, for the Muslims, would have been just that..... an Ocean; a large, seemingly eternal waterway with no imaginable peoples or tangible lands in distant sight.
I am doubtful that the Medieval Muslims would have known about the Incas, Aztecs or the Cherokee and Mohawk nations within the Eastern region of Ancient America. If they had any knowledge of their existence, it did not appear to be a high priority for future conquest and conversion. However, the Medieval Muslims would have been aware of the Canary Islands-(West of Morocco), as well as the Atlantic coastal regions of Spain, France and Britain, though probably not beyond the West European coast. As far as I know, there are no maps, travel writings, historical texts or other primary sources which document, state or sketch a Muslim expedition to the Americas during Medieval times. Of course, with
advancements in archaeological technology, as well as Geographic Information Systems/GIS, one may discover a retrieve a lost history that would prove the existence of such expeditions. However, until such a discovery materializes, there is currently no evidence that the Medieval Muslims "visited America before Columbus".