The spontaneous spreading of liquid droplets is studied by molecular modeling simulations. By considering very large systems, we are able to study the influence of the solid-liquid interactions on the overall wetting dynamics. It is shown how microscopic parameters, such as the mobility of the molecules near the solid-liquid interface, can be measured. At the same time, relevant macroscopic parameters, such as dynamic contact angles and flow fields, are calculated from the simulations. The results strongly support the microscopic validity of the molecular-kinetic model of wetting.