A high speed connector (106) with reduced crosstalk utilizes individual connector support frames (121, 122) that are assembled together to form a block of connector units (112). Each such unit supports a column of conductive terminals (113) in two spaced-apart columns. The columns 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 the pair of columns and they are closely spaced together so as to define within the pair of columns, a serpentine pattern of ground shields that cooperate to act as a single “pseudo” shield within each pair of columns. The ground shields are substantially larger in width (GW) than the differential signal terminal pairs (SPW) to provide more effective signal isolation.