  The use of the symbol $\lor$ for disjunction in formal logic is ubiquitous.
Where did it come from? The paper details the evolution of the symbol $\lor$ in
its historical and logical context. Some sources say that disjunction in its
use as connecting propositions or formulas was introduced by Peano; others
suggest that it originated as an abbreviation of the Latin word for "or", vel.
We show that the origin of the symbol $\lor$ for disjunction can be traced to
Whitehead and Russell's pre-Principia work in formal logic. Because of
Principia's influence, its notation was widely adopted by philosophers working
in logic (the logical empiricists in the 1920s and 1930s, especially Carnap and
early Quine). Hilbert's adoption of $\lor$ in his Grundz\"uge der theoretischen
Logic guaranteed its widespread use by mathematical logicians. The origins of
other logical symbols are also discussed.
