His return to Angostura was a sort of national festival.
The bitterness is imparted by such substances as bitter orange rind, gentian, rhubarb, quassia, cascarilla, angostura, quinine and cinchona.
Bitters are usually sold under the name of the substance which has been used to give them the predominant flavour, such as orange, angostura or peach bitters, &c. The alcoholic strength of bitters varies, but is generally in the neighbourhood of 40% of alcohol.
They are both the same up to one ingredient and that is Angostura bitters.
I tried them side-by-side and I liked the Mojito recipe that used the Angostura bitters better.