  We report the total and differential cross sections for $J/\psi$
photoproduction with the large acceptance GlueX spectrometer for photon beam
energies from the threshold at 8.2~GeV up to 11.44~GeV and over the full
kinematic range of momentum transfer squared, $t$. Such coverage facilitates
the extrapolation of the differential cross sections to the forward ($t = 0$)
point beyond the physical region. The forward cross section is used by many
theoretical models and plays an important role in understanding $J/\psi$
photoproduction and its relation to the $J/\psi-$proton interaction. These
measurements of $J/\psi$ photoproduction near threshold are also crucial inputs
to theoretical models that are used to study important aspects of the gluon
structure of the proton, such as the gluon Generalized Parton Distribution
(GPD) of the proton, the mass radius of the proton, and the trace anomaly
contribution to the proton mass. We observe possible structures in the total
cross section energy dependence and find evidence for contributions beyond
gluon exchange in the differential cross section close to threshold, both of
which are consistent with contributions from open-charm intermediate states.
