This paper presents new parton distribution functions (PDFs) for the proton, derived from a global analysis of hard scattering data within the framework of perturbative quantum chromodynamics (QCD). The analysis incorporates recent experimental data from deep-inelastic scattering (DIS), vector boson production, and single-inclusive jet production, as well as new theoretical developments. Two families of PDFs, CT10 and CT10W, are presented: CT10 excludes high-luminosity W lepton asymmetry data, while CT10W includes them. The CT10W PDFs are obtained by moderately increasing the χ² weights of the DØ Run-II lepton asymmetry data to ensure an acceptable fit. Theoretical advancements include a more consistent treatment of systematic uncertainties, a revised method for computing χ² to ensure consistency with data, and more flexible parametrizations for certain parton flavors. The CT10 analysis includes new precise experimental data in various scattering processes, such as DIS, vector boson production, and single-inclusive jet production. The combined HERA-1 data set significantly reduces the PDF uncertainty, and the CT10W PDFs show improved agreement with experimental data, particularly in the rapidity distribution of Z boson production. The CT10 and CT10W PDFs are compared with previous PDF sets, such as CTEQ6.6 and CT09, and their impact on various processes at the Tevatron and LHC is discussed. The CT10W PDFs show a more accurate description of the W and Z boson production cross sections, particularly in the Tevatron Run-II. The CT10W PDFs also exhibit a reduced uncertainty in the d/u ratio, which is crucial for understanding the flavor content of the proton. The analysis highlights the importance of including high-luminosity data in PDF fits and demonstrates the sensitivity of the W lepton asymmetry to the d/u ratio. The results show that the CT10W PDFs provide a better fit to the experimental data, particularly in the rapidity distribution of Z boson production. The CT10 and CT10W PDFs are used to study various processes at the Tevatron and LHC, including jet pair production, electroweak and Higgs boson production, and processes beyond the Standard Model. The analysis concludes that the CT10W PDFs are more accurate and reliable for collider physics applications.This paper presents new parton distribution functions (PDFs) for the proton, derived from a global analysis of hard scattering data within the framework of perturbative quantum chromodynamics (QCD). The analysis incorporates recent experimental data from deep-inelastic scattering (DIS), vector boson production, and single-inclusive jet production, as well as new theoretical developments. Two families of PDFs, CT10 and CT10W, are presented: CT10 excludes high-luminosity W lepton asymmetry data, while CT10W includes them. The CT10W PDFs are obtained by moderately increasing the χ² weights of the DØ Run-II lepton asymmetry data to ensure an acceptable fit. Theoretical advancements include a more consistent treatment of systematic uncertainties, a revised method for computing χ² to ensure consistency with data, and more flexible parametrizations for certain parton flavors. The CT10 analysis includes new precise experimental data in various scattering processes, such as DIS, vector boson production, and single-inclusive jet production. The combined HERA-1 data set significantly reduces the PDF uncertainty, and the CT10W PDFs show improved agreement with experimental data, particularly in the rapidity distribution of Z boson production. The CT10 and CT10W PDFs are compared with previous PDF sets, such as CTEQ6.6 and CT09, and their impact on various processes at the Tevatron and LHC is discussed. The CT10W PDFs show a more accurate description of the W and Z boson production cross sections, particularly in the Tevatron Run-II. The CT10W PDFs also exhibit a reduced uncertainty in the d/u ratio, which is crucial for understanding the flavor content of the proton. The analysis highlights the importance of including high-luminosity data in PDF fits and demonstrates the sensitivity of the W lepton asymmetry to the d/u ratio. The results show that the CT10W PDFs provide a better fit to the experimental data, particularly in the rapidity distribution of Z boson production. The CT10 and CT10W PDFs are used to study various processes at the Tevatron and LHC, including jet pair production, electroweak and Higgs boson production, and processes beyond the Standard Model. The analysis concludes that the CT10W PDFs are more accurate and reliable for collider physics applications.