Which constitutional principle did president truman violate?

President Truman violate violated the separation of powers principle. This is the idea that a Government's power should be split up between different branches to avoid one arm having too much power. Truman violated this principle President Harry Truman asserted a unilateral executive decision to go to war.

d - failures.

the only attempted british colony in north america before 1600 was roanoke, virginia, which was a total failure. england claimed several areas, including newfoundland, but made no sustainable attempts to colonize them before 1600.