There are a wide variety of Blues Progressions that take their origins from the standard 12 Bar Blues form. Over the years these have evolved into more various and complex arrangements by the likes of John Coltrane and Thelonius Monk and although there are instances where there may be 8, 14, 16 or 24 bar blues the foundation 12 Bar form remains, for the most part, the same.
It is important to remember that Blues Music always uses Dominant 7th chords and so it stands separate from Western Music Theory. Although the chord progressions can be marked numerically as in a Diatonic Chord sequence, when we state that Blues is in a key that does not mean that all of the chords relating to the scale of that key apply. A Blues in F, for example, refers to the starting chord of the blues progression form. Some of the other chords that go in the key of F (G min, Amin, etc) are not necessarily relevant.
Blues Music takes its roots in the deep south of the USA at the end of the 19th century and its influences from European, African and Latin music. The Blues has been massively influential on Jazz music. Almost every one of the Jazz Superstars from Miles Davis to Count Basie has incorporated Blues numbers in their repertoire and contributed to its form.