Electrical connector includes a housing, signal contacts, and ground shields. The signal contacts are coupled to the housing and positioned for mating with mating signal contacts of a mating connector. The ground shields are coupled to the housing and at least partially surround the signal contacts to shield the signal contacts. The ground shields are plated with a ground-material composition along one or more contact segments of the ground shields that come into compression engagement with one or more other conductive members. The ground-material composition includes a tin-nickel (Sn/Ni) alloy plating layer. The signal contacts are plated with a signal-material composition that is different than the ground-material composition.