An electrical interconnection system with high speed, differential electrical connectors. The connector is assembled from wafers each containing a column of conductive elements, some of which form differential pairs. Skew control is provided for at least some of the pairs by providing a profile on an edge of the shorter signal conductor of the pair. The profile may contain multiple curved segments that effectively lengthen the signal conductor without significantly impacting its impedance. For connectors in which ground conductors are included between adjacent pairs of signal conductors, patterned segments of varying parameters may be included on edges of the signal conductors and ground conductors to equalize electrical lengths of all edges in a set of edges for which there is common mode or differential mode coupling as a signal propagates along each pair. Such features for skew control may be used in combination with other skew control features. The features used may vary depending on the location of the pair within the column.