  We present a novel method for including the effects of early (pre-supernova)
feedback in simulations of galaxy evolution. Rather than building a model which
attempts to match idealized, small-scale simulations or analytic
approximations, we rely on direct observational measurements of the time-scales
over which star-forming molecular clouds are disrupted by early feedback. We
combine observations of the spatial de-correlation between molecular gas and
star formation tracers on $\sim100$~pc scales with an analytic framework for
the expansion of feedback fronts driven by arbitrary sources or mechanisms, and
use these to constrain the time-scale and momentum injection rate by early
feedback. This allows us to directly inform our model for feedback from these
observations, sidestepping the complexity of multiple feedback mechanisms and
their interaction below the resolution scale. We demonstrate that this new
model has significant effects on the spatial clustering of star formation, the
structure of the ISM, and the driving of outflows from the galactic plane,
while preserving the overall regulation of the galaxy-integrated star formation
rate. We find that this new feedback model results in galaxies that regulate
star formation through the rapid disruption of star-forming clouds, rather than
by highly efficient, global galactic outflows. We also demonstrate that these
results are robust to stochasticity, degraded numerical resolution, changes in
the star formation model parameters, and variations in the single free model
parameter that is unconstrained by observations.
