The true "march music era" existed from 1850 to 1940's as it slowly became shadowed by the coming of jazz. Earlier marches, such as the ones from Ludwig Van Beethoven, Wolfgang Mozart, and George Frideric Handel tended to be part of a symphony or a movement in a suite. Despite the age of these marches, the history it holds and its performance in the United States, they are generally not thought of as "typical American march music".
Marches and the Military Band
It is said that the origins of march music began before the Gunpowder Age during which armies would maintain their troops' morale by marching with music playing, whether that be from the beat of a drum or fife. American march music showed during the Revolutionary War and earlier wartime conflicts, in which a fife and snare drum would play while the troops marched to battle. This is why it can be said that march music is a military's music.
While the tradition of soldiers playing music while marching into battle had ended soon after the American Civil War (mid 1800’s), military bands continued to perform marches during related ceremonies and other events. This actually spawned a whole new tradition of playing marches as a source of entertainment.
John Philip Sousa
Marches and the Concert Band
Around the late 1800’s and early 1900’s, most towns, organizations, theaters and even companies would have their own band. These bands, currently known today as community bands, would perform their music at special events much like the military band, but would often play at simple scheduled concerts and tours (such as the traditional gazebo concerts). By this time, published marches were plentiful due to prolific composers such as John Philip Sousa, Karl L. King and Henry Fillmore. Marches became a staple in the repertoire of these concert bands and can hence explain how the popularity of the march spread so rapidly across the world.
Marches and the Circus
Marches were further popularized with performances by circus bands. During the same period of the community band/concert band, circuses such as the Barnum & Bailey’s Circus, and the Ringling Bros. Circus would have live music being performed by their own bands. The marches played were often a special variety of the march known descriptively as “Screamers”, “Two-Steps”, and “Cake Walks”. These marches served the purpose of exciting the crowd while circus acts were taking place.
Marches and the Marching Band
Again, during the same period college marching bands were also beginning to form. It is a fact that march composers would often dedicate marches to university bands. Marches were performed during half-time shows and pep-rallies. Marches were indeed heard everywhere.
The John Philip Sousa Revolution
American composer John Philip Sousa did indeed strongly revolutionize the march. His overall prolific writing of said quality marches added that much to its popularity. According to Sousa researcher Paul Bierley, Sousa’s marches were gems of simplicity and understatement, with rousing counterpoint and overall energy. Sousa also is said to have standardized the traditional march form (see below) and added considerably to the easy-listening genre of music.