I assume the colonies were named by the Monarch or the first colonist. But what about states that came later? Also how did they decide where to split territory. The Louisiana purchase was huge but the states is fairly same.
This is a fairly complex question, one that really needs to be divided up. For some states (like Maryland or Virginia) their formal names have complex histories that are both fascinating but also detailed and nuanced. Diving into something such as border divisions and/or land disputes is also quite complicated as well (All of the 13 states didn't even have agreed upon boundaries until 1781 which was one of the most contentious parts of trying to pass the Articles of Confederation). Because of all this, the answers would a) be incredibly too long, and b) cover far too many topics, and c) cover far too long of a time period (you are essentially asking us to cover borders and names from the early 1600s until the early 1800s with the Louisiana Purchase).
Could you possibly narrow down your request to specific states and/or time periods?