The Open Door policy—first initiated in 1899, with a follow-up missive in 1900—was significant in its attempt by the United States to establish an international protocol of equal privileges for all countries trading with China and to support China's territorial and administrative integrity. Hope this helped:)
The single event that most tarnished Ford's presidency was his decision to pardon Nixon. He also, however, presided over the worst US economy since the Great Depression.