This image depicts two maps of Texas House Districts in Harris County, home to Houston. Through 1961, the rural and white-male dominated state Legislature routinely did its best to restrict representation for big cities and their resident minorities. One device long used was a system of at-large seats for large urban counties. Thus, as the map on the left shows, in 1961 Harris County was treated as one state House district (22) containing more than 1.2 million people. All registered voters in the county could participate in voting for each of the 12 legislative seats in the district. Twelve seats worked out to more than 100,000 people per representative, a much higher figure than the state average of about 64,000. Moreover, the at-large system meant that minority voters concentrated in some parts of Houston or the surrounding county did not have enough votes to elect someone of their chosing to the Legislature since their votes were diluted among the votes of all the other people in the county. By 1971, as the map on the right shows, U.S. Supreme Court decisions and federal legislation had forced dramatic change on how districts were to be drawn. By 1971, the state Legislature could no longer use an at-large system but had to divide large urban counties into single-member districts. Moreover, the number of representatives to which Harris County was entitled for its more than 1.7 million people grew to 23 from 12, equalizing the populations represented in each Harris County House district with those of districts across the state in keeping with the principle of "one person, one vote."

This cartoon image of four representatives and their constitutents illustrates the creation of a majority-minority district. In this image, the blue representative third from the left has only blue constitutents. The other three red representatives have one or two blue constituents in addition to majorities of red constituents and the odd purple constituent. When districts were drawn and constituencies created by the resulting maps, blue citizens were grouped or packed into one district where they would be in the majority rather than dividing them among red-majority districts.