During the American Civil War, most brass bands used a branch of the brass family known as saxhorns, which, by today's standards, have a narrower bore taper than tuba—the same as true cornets and baritones but distinct from trumpets, euphoniums, and others with different tapers or no taper. Around the start of the Civil War, saxhorns manufactured for military use in the USA were commonly wrapped with the bell pointing backwards over the player's shoulder, and these were known as over-the-shoulder saxhorns, and came in sizes from cornets down to E basses. However, the E bass, even though it shared the same tube length as a modern E tuba, has a narrower bore and as such cannot be called by the name tuba except as a convenience when comparing it to other sizes of the saxhorn.
during the american civil war most brass bands used a branch of the brass family known as saxhorns which by today's standards have a narrower bore taper than tuba—the same as true cornets and baritones but distinct from trumpets euphoniums and others with different tapers or no taper around the start of the civil war saxhorns manufactured for military use in the usa were commonly wrapped with the bell pointing backwards over the player's shoulder and these were known as over-the-shoulder saxhorns and came in sizes from cornets down to e basses however the e bass even though it shared the same tube length as a modern e tuba has a narrower bore and as such cannot be called by the name tuba except as a convenience when comparing it to other sizes of the saxhorn