I just wrote up my own question about this after doing a little digging. I'm just going to repost here and delete the other comment. By our powers combined!

So, apparently today Turkish President Recep Tayyip Erdogan claimed

Muslim sailors arrived in America in 1178.

There is nothing implausible about this, I suppose, except knowing enough about this contact to supply a precise date. The BBC article isn't very useful, mentioning only an old article by Youssef Mroueh. I was able to find something that seems to be an abstract of some sort by this guy. There are some claims to surviving evidence in the old world - maps, sailor stories, and such, and that's all fine, but apparently there's new world evidence as well?

The ruins of mosques and minarets with inscriptions of Quranic verses have been discovered in Cuba,Mexico,Texas and Nevada....

the existence of the Muslim schools at Valley of Fire, Allan Springs, Logomarsino, Keyhole, Canyon, Washoe and Hickison Summit Pass (Nevada), Mesa Verde (Colorado), Mimbres Valley (New Mexico) and Tipper Canoe(Indiana) dating back to 700-800 CE.

700 CE! Yikes!

texts, diagrams and charts representing the last surviving fragments of what was once a system of schools - at both an elementary and higher level. The language of instruction was North African Arabic written with old Kufic Arabic scripts.

I feel like as someone who has TAed for world history courses and may have to teach them in the future, I shouldn't need the President of Turkey to alert me to pre-Columbian architecture and texts existing in the Americas. Does anyone know what's going on here?

I don't need to know about Erdogan - no breaking the 20 year rule - I just want to know what he's talking about and if this guy Mroueh the BBC cites has something.

hi! you may find something of interest in these posts

• Is There Any Evidence That Moors Reached The Americas Before Columbus?

• How long did it take for knowledge of the "discovery" of America to make it to the Muslim world? Did any Muslim leaders send subsequent expeditions to the New World?

• Can anybody elaborate on the Theory that Africans navigated across the Atlantic long before Columbus?

• Is there any truth to claims that Africans arrived in the New World before Columbus' voyages?

• I've heard rumours since my grade 11 history class that the Egyptians crossed the Atlantic and visited North America long before the rise of the Roman civilization. Does anyone have sources confirming this, or is it just a rumour?

I heard this a lot within Muslim circles, and quite suprised that Erdogan repeated it publicly. Here's my take: Problems with claiming that “Muslims discovered America”. Feel free to read, and my opinion is:

While there is a non zero possibility that an Muslim voyage may have visited the Americas before Columbus, there doesn’t seem to be enough evidence to support this with a reasonable confidence. Moreover, even when it’s true, the point is moot anyway because historians already know that Columbus was not in fact the first to cross the Atlantic. The Vikings got there first. What was important was not the primacy, but the decisive change that followed it. So even if there was such thing as the Muslim discovery of America, it would not displace Columbus’ journey of its importance.

I can't confirm or deny anything around the 12th century. However, Gavin Menzies (a British historian) has made controversial claims that Zheng He, a Muslim Chinese admiral, may have reached the America's during his 14th century voyages for the Ming Dynasty before Columbus. Here is a link to an article that summarizes his claims: http://www.dailymail.co.uk/news/article-2449265/Who-Discovered-America--Controversial-historian-Gavin-Menzies-claims-Chinese-reached-New-World-first.html

You can also find more of the pre-Colombian voyage theories to the Americas in the History Channel "Who Really Discovered America?" documentary. These are just theories and very few trained historians believe the evidence for the various theories presented.

The Zheng He theory is just a theory of course. I am not convinced by his evidence but it is an entertaining idea. I teach history to middle schoolers and I have a degree in history if that adds to my credibility for this post.