Ameliorate the Open Door Policy

Directions: Grammatically ameliorate the sentence below; there is a missing colon (:) and one misspelled word.

The Open Door Policy was a U.S. diplomatic principle from the late 1800s and early 1900s it insisted that all countrys should have equal trading rights in China.

The Open Door Policy was a U.S. diplomatic principle from the late 1800s and early 1900s: it insisted that all countries should have equal trading rights in China.