They have trade partners such as china and other islands
The Mayflower Compact was important for a number of reasons.
First, it kept mutiny at bay.
But it was also a good first step as the new colonists figured out what rules they wanted to live by.
By setting up a system with majority rule, they ensured that there would always be consensus for decisions and would ensure that everybody would win some and everybody would lose some. The system would feel fair as they faced tough years ahead.
The Open Door policy was written in 1899. The U.S. was interested in acquiring cheaper goods (mainly cotton) from foreign markets.
John Hays wrote this policy to protect the privileges among countries that were trading with China. He wanted countries to have equal access to ports open to trade in China, and to avoid a monopoly.
The first note in the Open Door Policy said that (1) each great power should maintain free access to a treaty port or to any other vested interest within its sphere.