Washington, D.C. native and legendary bandmaster John Philip Sousa (1854-1932) wrote a dozen operettas, six full-length operas, and over 100 marches, earning the title “March King”. He enlisted in the United States Marine Corps at an early age and went on to become the conductor of the President’s Own United States Marine Band at age 26. In 1892 he formed “Sousa and his Band”, which toured the United States and the world under his directorship for the next forty years to great acclaim. Not only was Sousa’s band hugely popular, but it also exposed audiences all over the world to the latest, cutting-edge music, bringing excerpts of Wagner’s Parsifal to New York a decade before the Metropolitan Opera staged it, and introducing ragtime to Europe, helping to spark many a composer’s interest in American music.
Sousa wrote The Thunderer in 1889. The origin of its title is unclear. According to Marcus Neiman, the march was dedicated to Sousa’s Masonic organization, so it may have some connection to part of the Masonic symbolism or a person within the organization. The title may also refer to the thunderous trumpet and drum parts in the first half of the march. Whatever the case may be, it has stood the test of time as one of Sousa’s most accessible, easily playable marches. For more, look at Wikipedia and the Band Music PDF Library (which also has a full set of performable parts.) You can get even more free editions of The Thunderer at IMSLP, as well as the new definitive edition with the US Marine Band’s Complete Marches of John Philip Sousa.
John Philip Sousa on Wikipedia
The Thunderer in a modern performance by the US Marine Band:
And again by Sousa himself and the US Marine Band in a vintage 1890 recording: