  Electromagnetism, the strong and the weak interaction are commonly formulated
as gauge theories in a Lagrangian description. In this paper we present an
alternative formal derivation of U(1)-gauge theory in a manifestly covariant
Hamilton formalism. We make use of canonical transformations as our guiding
tool to formalize the gauging procedure. The introduction of the gauge field,
its transformation behaviour and a dynamical gauge field Lagrangian/Hamiltonian
are unavoidable consequences of this formalism, whereas the form of the free
gauge Lagrangian/Hamiltonian depends on the selection of the gauge dependence
of the canonically conjugate gauge fields.
