Hadronic resonances emerge from strong interactions encoding the dynamics of quarks and gluons. The structure of these resonances can be probed by virtual photons parametrized in transition form factors. In this study, twelve N^{*} and Δ transition form factors at the pole are extracted from data with the center-of-mass energy from πN threshold to 1.8 GeV, and the photon virtuality 0≤Q^{2}/GeV^{2}≤8. For the first time, these results are determined from a simultaneous analysis of more than one state, i.e., ∼10^{5} πN, ηN, and KΛ electroproduction data. In addition, about 5×10^{4} data in the hadronic sector as well as photoproduction serve as boundary conditions. For the Δ(1232) and N(1440) states our results are in qualitative agreement with previous studies, while the transition form factors at the poles of some higher excited states are estimated for the first time. Realistic uncertainties are determined by further exploring the parameter space.