Virginia's state legislature approved a bill requiring school textbooks to include the Korean name for the sea between Japan and South Korea, in a major win for Seoul.
The two key US allies, battling renewed tensions dating from imperial Japan, fought a proxy battle over the textbook change, with their respective ambassadors visiting the Southern state's capital Richmond repeatedly.
Korean American activists gained the upper hand in their effort to address the historical grievances with Japan that rouse deep passions in South Korea.
The Virginia House of Delegates voted 81-15 to approve the measure yesterday requiring "that all textbooks approved by the Board of Education (after July 1, 2014) when referring to the Sea of Japan, shall note that it is also referred to as the East Sea".
The bill, which has already being cleared by the Senate now awaits the signature of Democratic Governor, Terry McAuliffe, who is widely expected to sign it into law.
There was no immediate response from Japan, but the South Korean government, which had enthusiastically supported the bill, welcomed its passage.
"This is the result of efforts by our compatriots in the US to make the name of the East Sea popular, and we highly appreciate it," said foreign ministry's spokesman Cho Tai-Young.
Japan, which opposed the textbook change and hired a team of lobbyists to defend its position, had stressed that "Sea of Japan" was the only name for the body of water that was recognised by the United Nations and the International Hydrographic Organisation.
Koreans say the name is a legacy of Japanese colonialism, and prefer to use "East Sea".
The Virginia battle was an unenviable choice for the state, where Asian Americans are increasingly seen as a critical voting bloc for President Barack Obama's Democratic Party. Japan forms a huge trading partner of the United States with an investment of nearly USD 1 billion in the past five years, second only to Germany.
