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We present an overview of the Carnegie-Chicago Hubble Program, an ongoingprogram to obtain a 3 per cent measurement of the Hubble constant usingalternative methods to the traditional Cepheid distance scale. We aim toestablish a completely independent route to the Hubble constant using RR Lyraevariables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNeIa). This alternative distance ladder can be applied to galaxies of any HubbleType, of any inclination, and, utilizing old stars in low density environments,is robust to the degenerate effects of metallicity and interstellar extinction.Given the relatively small number of SNe Ia host galaxies with independentlymeasured distances, these properties provide a great systematic advantage inthe measurement of the Hubble constant via the distance ladder. Initially, theaccuracy of our value of the Hubble constant will be set by the five GalacticRR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensorparallaxes. With Gaia, both the RR Lyrae zero point and TRGB method will beindependently calibrated, the former with at least an order of magnitude morecalibrators and the latter directly through parallax measurement of tip redgiants. As the first end-to-end "distance ladder" completely independent ofboth Cepheid variables and the Large Magellanic Cloud, this path to the Hubbleconstant will allow for the high precision comparison at each rung of thetraditional distance ladder that is necessary to understand tensions betweenthis and other routes to the Hubble constant.

The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using only Population II Distance Indicators