Please go easy on me this is my first history, and I am not as smart as most of the people here.
Welcome to Norse America!
In this timeline the Vikings continue to explore and travel across the Americas. I don't have a specific POD yet, but I will come up with one as I continue along. The general idea is that the Norse get wind of Vinland and make massive expansions on the continent eventually reaching a population of 5000 Vikings by the end of the year 1300, they bring with them the designs of longships and the concepts of sailing, as well as iron swords and shields, and even introduce horses to the Americas much earlier than OTL. The fall of the Vikings lead to the rise of the Native Americans with a new culture of people called the Norse-Skraelings emerging as a dominant ethnicity in the north east. The natives strive and suffer with the introduction of new diseases which obliterate a majority of natives on the eastern seaboard. Though through their suffering the Natives build powerful armies and nations, some of which begin to rival European powers at later dates, and lead to a massive shift in the global outcome of immigration, population, religion, government, and culture that change the world greatly.