# Who was the first pointing out the $U(1)$-gauge theories common structure?

It is well-known that in each $U(1)$-gauge theory one can define, in analogy with electromagnetism, a 1-form connection and an associated 2-form of curvature on an appropriate (principal) bundle, dependent upon the concrete problem. Nowadays this fact has become common lore of theoretical physics, however I'd like to know, for reference purpose, who was the first that pointed out such an analogy. Does anyone know and, if possible, provide a reference to the original article?