A high speed connector with reduced crosstalk utilizes individual connector support frames that are assembled together to form a block of connector units in a vertical arrangement. Each such unit supports an array of conductive terminals that are arranged in two spaced-apart rows. The rows have differential signal terminal pairs separated from each other by larger intervening ground shields that serve as ground terminals. The ground shields are arranged in alternating fashion within each row of terminals and they are closely spaced together so as to define within the rows of each connector unit, a horizontal serpentine pattern of ground shields that cooperate to act as a single “pseudo” shield within each pair of terminal rows.