Complex sentence: The organization's name was amended to "Regular Army and Navy Union of the United States of America" on November 11,1891, and was officially adopted by the original society on October 19,1899.
Split into simpler sentences: The organization's name was amended to "Regular Army and Navy Union of the United States of America" on November 11,1891. This name was officially adopted by the original society on October 19,1899.