We know the Chinese were in N America in antiquity, including perhaps an attempt at Buddhist missionizing in the 400's AD.
Deep in antiquity, Chinese explorers had no doubt tried to survey America in their way, and there is a reference in the Chinese classics to the "Great Eastern Waste" and to the Grand Canyon.
The best evidence is a reference to the width of the Pacific as so many li, about correct, and then say the Great Eastern Waste is reached, and if it is crossed, [again a number of li is given, about correct at 3000 miles]...another ocean is found, great and blue and trackless.
Good grief. I hadn't thought about that book in years. I still have a copy. Pale Ink by Henriette Mertz originally published in 1953. (Along about the time of the book "Worlds in Collision" by Immanuel Velikovsky)
Later sometime in the 70's it was published again with the Title: God's from the far east.
The second title was due to the popularity at that time of one Erich Von Däniken and his book: Chariots of the gods
After Von Däniken's success with his "gods" book(s), everybody "jumped on the old band wagon" with a "gods" title and that even brought back into print the long forgotten work of Velikovsky and others including Pale Ink with a "gods" title.
I had almost forgotten about all the Von Däniken inspired hullabaloo till you remined me
Take care
God Bless