About 87 years before Christopher Columbus had discovered the Americas, a Chinese Admiral named "Zheng He" sailed his vast fleet between 1405 to 1433 to Southeast Asia, India, Middle East, Africa, and even to the outer fringes of Europe. (And even traveled possibly to the Americas.)
Zheng He was born of a Muslim family in Yunnan in the southwestern part of China in 1371, and his ancestors were Arabs who immigrated into China & intermarried with the locals during the Tang and Song dynasties. (However, despite his Muslim family background, he became tolerant of all faiths.) Zheng rose through the ranks as a soldier, and was a military veteran of several campaigns against the Mongols from the Yuan Dyansty. He helped the Emperor Cheng Zu in his rise to the throne, and establishing the Ming Dynasty. (1368-1644) He also became a close friend, and a personal adviser to the Emperor. (He was also a eunuch, and never married for obvious reasons.)
In 1404, Emperor Cheng Zu commissioned Zheng He to go out & explore the world, and gave him the authority to build one of the the biggest fleet that history has ever known. (The Emperor wanted to know what was out there, and the exploration was also for establishing future colonies & to establish new trade sea routes.)
Zheng He's ships were more bigger & in some ways, more advanced technologically than Christopher Columbus's ships. (In some ways, they were even more ship worthy than Columbus's "La Santa Maria".) From 1402 to 1433, his fleet went as far as Southeast Asia, Middle East, India, Africa, and even to the outer fringes of Europe. (His fleet may even have traveled to the Americas.)
Unfortunately, Emperor Cheng Zu passed away in 1424, and a new Hongxi Emperor rose to the throne. The new Emperor, ordered the fleet to return to China, and banned all future explorations. The close minded Emperor felt that China was already the center of the universe, and to him, any future exploration, as well as having establishing future colonies were a complete waste of time & resources. Zheng He fell into disfavor, and fell into obscurity. He was believed to have died at sea during the return trip to the to Hormuz in 1433, and his body was never recovered.
Had Zheng He been allowed to continue with his journeys, and expand new colonies, the history of the Americas would have turned out very differently.
(It would have been the United States of China, instead of America.) It would also have been likely that Japan, Philippines, Guam, Hawaii, Polynesia, and even Australia would have been annexed as well, since China was a global power at that time. (Europe had barely just climbed out of the Middle Ages, and were still involved in constant wars in their continent, when Admiral Zheng He started exploring the world.)