The St. George recoil separator (Strong Gradient Electromagnetic Online Recoil separator for capture Gamma Ray Experiments) has been commissioned by comparing its design parameters with the ones measured; the angular and energy acceptance has been characterized; the HIPPO gas target has been rebuilt and recommissioned; a scalable separator tune has been determined; and the rejection has been characterized. St. George has then been used to measure three well known resonance strengths in the 14N(α,γ)18F reaction. This reaction is important to furthering understanding of nuclear astrophysical systems and reaction networks involved in nucleosynthesis, particularly as a precursor to a neutron source reaction in AGB stars for s-process nucleosynthesis. The determined absolute resonance strengths are compatible with the literature values, proving that St. George can be used to measure alpha-capture reactions of astrophysical interest.