  Few observational constraints exist for the tidal synchronization rate of
late-type stars, despite its fundamental role in binary evolution. We visually
inspected the light curves of 2278 eclipsing binaries (EBs) from the Kepler
Eclipsing Binary Catalog to identify those with starspot modulations, as well
as other types of out-of-eclipse variability. We report rotation periods for
816 EBs with starspot modulations, and find that 79% of EBs with orbital
periods less than ten days are synchronized. However, a population of short
period EBs exists with rotation periods typically 13% slower than synchronous,
which we attribute to the differential rotation of high latitude starspots. At
10 days, there is a transition from predominantly circular, synchronized EBs to
predominantly eccentric, pseudosynchronized EBs. This transition period is in
good agreement with the predicted and observed circularization period for Milky
Way field binaries. At orbital periods greater than about 30 days, the amount
of tidal synchronization decreases. We also report 12 previously unidentified
candidate $\delta$ Scuti and $\gamma$ Doradus pulsators, as well as a candidate
RS CVn system with an evolved primary that exhibits starspot occultations. For
short period contact binaries, we observe a period-color relation, and compare
it to previous studies. As a whole, these results represent the largest
homogeneous study of tidal synchronization of late-type stars.
