[6] After suspending all activities during World War II, Japan Society expanded under the leadership of John D. Rockefeller III.

[7][8][9] Japan Society spent the next forty years hosting events in honor of Japanese royalty, giving annual lectures on a wide range of topics, and presenting art exhibits that drew in thousands of New Yorkers.

[7] Japan Society was soon incorporated under New York law and finally found a home near one of Russell's work offices, though it continued to relocate throughout its history before its current headquarters was opened in 1971.

The organization began sponsoring trips to the country, publishing books, and sent a report to the Department of Education about the portrayal of Japan in American textbooks.

[7] In 1915, Dr. Takamine Jōkichi, a founding member of the Japan Society and the founder of the Nippon Club, hosted a diplomatic banquet in New York City to honor the visit of Baron Eiichi Shibusawa to the United States.

[10] Japan Society remained active during World War I, operating as it had for the last seven years, but the organization became more political when it began associating with the Anti-Alien Legislation Committee, an advocacy group that spoke out against yellow peril.

[7] On February 27, 1934, the Japan Society's Annual Dinner event honored the visit of Prince Iyesato Tokugawa.

Designed by Junzo Yoshimura, whose work also includes Asia Society's headquarters, it became the first building in New York of contemporary Japanese architecture.