Cosmic Distances Calibrated to 1% Precision with Gaia EDR3 Parallaxes and Hubble Space Telescope Photometry of 75 Milky Way Cepheids Confirm Tension with ΛCDM

We present an expanded sample of 75 Milky Way Cepheids with Hubble Space Telescope (HST) photometry and Gaia EDR3 parallaxes which we use to recalibrate the extragalactic distance ladder refine determination constant. All HST observations were obtained same instrument (WFC3) filters (F555W, F814W, F160W) used for imaging in Type Ia supernova (SN Ia) hosts. The WFC3 spatial scanning mode mitigate saturation reduce pixel-to-pixel calibration errors, reaching a mean photometric error 5 millimags per observation. new parallaxes, vastly improved since DR2, Period-Luminosity (PL) relation these simultaneously calibrate parallax offset. resulting geometric Cepheid luminosities has 1.0% precision, better than any alternative anchor. Applied SNe~Ia, it results measurement constant 73.0 +/- 1.4 km/sec/Mpc, good agreement conclusions based on earlier data releases. also find slope PL Way, metallicity dependence its zeropoint, be values derived from other galaxies. In combination best complementary sources calibration, reach 1.8% precision H_0=73.2 1.3 4.2 sigma difference prediction Planck CMB under LambdaCDM. expect ~1.3% near term ~40 SNe