It was just because China and the United States got a common understanding on the issue of emperor system, the polity of Japan were not involved in the Cairo Declaration, which provided a base...

正是由于中美两国在天皇制问题上达成了共识，故而《开罗宣言》没有涉及日本的国体问题，为后来天皇制的保留提供了一个存在的基础。

youdao

The writing on the stone says in large letters: Norton the First, Emperor of the United States and Protector of Mexico.

VOA: special.2009.12.14

They do not want people in Frisco oops,make that San Francisco to forget the first and only emperor of the United States.

VOA: special.2009.12.14

Some bought the newspapers just to read about the latest decree from the emperor of the United States.

VOA: special.2009.12.14