From WIKIPEDIA (see link for more details):
The Great White Fleet was the popular nickname for the powerful United States Navy battle fleet that
completed a journey around the globe from 16 December 1907, to 22 February 1909, by order of United
States President Theodore Roosevelt. Its mission was to make friendly courtesy visits to numerous
countries, while displaying America's new naval power to the world.
It consisted of 16 battleships divided into two squadrons, along with various escorts. Roosevelt sought to
demonstrate growing American martial power and blue-water navy capability. Hoping to enforce treaties
and protect overseas holdings, the United States Congress appropriated funds to build American naval
power. Beginning in the 1880s with just 90 small ships, over one-third of them wooden and therefore
obsolete, the navy quickly grew to include new modern steel fighting vessels. The hulls of these ships
were painted a stark white, giving the armada the nickname "Great White Fleet".
The badge below commemorated the visit of the Fleet to Japan in 1908. The Fleet stayed in Yokohama
Harbor from October 18 to the 25.
It is quite possible that I will not find any more Japanese badges commemorating this event, but since
this one I found is such a wonderful piece, I decided it deserved its own page.
Fantastic design! Implements the national
flags of the USA and Japan, and includes the
martial symbols of the Army (star), Navy
(anchor), and Cavalry (horseshoe).
Unusual reverse pin, probably intended to be
sipped into a pocket.
Inscribed: 'Welcoming the American Fleet.
Dinner with Army Minister Terauchi. Tokyo.'