An electrical connector includes a housing, signal contacts, and ground shields. The housing extends between a front end and a rear end and defines a cavity at the front end. The signal contacts are held by the housing and are arranged in pairs carrying differential signals. The signal contacts have mating ends in the cavity for mating with a mating connector. The ground shields are held by the housing and extend along the signal contacts in the cavity. The ground shields have center walls and side walls surrounding associated pairs of the signal contacts on at least two sides thereof. The ground shields each have a commoning feature extending outward from a corresponding side wall. The commoning feature mechanically engages another ground shield in a group of ground shields to electrically join the ground shields of the group within the cavity.