Since the late 19th century, map makers have experimented with various graphic techniques for displaying Presidential election results. One of the earliest and most complex attempts was published in anticipation of the 1888 election between Republican Benjamin Harrison and Democrat Grover Cleveland. Each state was overlaid by five rectangular bars. The first four bars were colored either red for a Republican majority or black for a Democratic majority, signifying the results of the four previous elections. The fifth bar was left blank for recording the 1888 results. A series of colored dots also signified the party affiliation of governors, senators, and representatives.
From the battle-ground of the presidential election in the October 6, 1888 issue of Harper's Weekly.