At approximately what latitude does the northern most part of the united states lie?

Northwest Angle, Minesotta is the northernmost place in the United States, It is the only place outside Alaska that is north of the 49th parallel, which constitutes the border between the U.S and Canada, from the Northwest Angle westward to the Strait of Georgia  Lake of the Woods separates the land area of the Angle from the rest of Minnesota. However it shares a land border with Canada.

Northernmost - Northwest Angle, Minnesota (49.38407°N, 95.15274° W)

answer; taking up arms to defend the nation;