  We use a new compilation of the hadronic $R$-ratio from available data for
the process $e^+e^-\to\mbox{hadrons}$ to determine the strong coupling,
$\alpha_s$. We make use of all data for the $R$-ratio from threshold to a
center-of-mass energy of 2 GeV by employing finite-energy sum rules. Data above
2 GeV, for which at present far fewer high-precision experimental data are
available, do not provide much additional constraint but are fully consistent
with the values for $\alpha_s$ we obtain. Quoting our results at the $\tau$
mass to facilitate comparison to the results obtained from analogous analyses
of hadronic $\tau$-decay data, we find $\alpha_s(m_\tau^2)=0.298\pm 0.016\pm
0.006$ in fixed-order perturbation theory, and $\alpha_s(m_\tau^2)=0.304\pm
0.018\pm 0.006$ in contour-improved perturbation theory, where the first error
is statistical, and the second error reflects our estimate of various
systematic effects. These values are in good agreement with a recent
determination from the OPAL and ALEPH data for hadronic $\tau$ decays.
