We calculate the contribution to the muon anomalous magnetic moment hadronic vacuum polarization from the connected diagrams of up and down quarks, omitting electromagnetism. We employ QCD gauge-field configurations with dynamical u, d, s, and c quarks and the physical pion mass, and analyze five ensembles with lattice spacings ranging from a ≈ 0.06-0.15 fm. The up-and downquark masses in our simulations have equal masses m l . We obtain, in this world where all pions have the mass of the π 0 , 10 10 a ll µ (conn.) = 630.1(8.3), in agreement with independent lattice-QCD calculations. We then combine this value with published lattice-QCD results for the connected contributions from strange, charm, and bottom quarks, and an estimate of the uncertainty due to the fact that our calculation does not include strong-isospin breaking, electromagnetism, or contributions from quark-disconnected diagrams. We obtain for the total order (α 2 ) hadronic-vacuum polarization to the muon's anomalous magnetic moment 10 10 a HVP,LO µ = 691(8) u,d (1) s,c,b (13) other , where the errors are from the light-quark connected contribution, heavy-flavor connected contributions, and omitted effects listed above, respectively. Our result agrees with both ab-initio lattice-QCD calculations and phenomenological determinations from experimental e + e − -scattering data. It is 1.7σ below the "no new physics" value of the hadronic-vacuum-polarization contribution inferred from combining the BNL E821 measurement of aµ with theoretical calculations of the other contributions. * christine.davies@glasgow.ac.uk † ruthv@fnal.gov