Systematic observations of magnetic field strength and polarity in sunspots began at Mount Wilson Observatory (MWO), USA in early 1917. Except for a few brief interruptions, this historical dataset continues till present. Here file Figs3_5.txt contains data shown in Figures 3-5; files Fig6a.txt and Fig6b.txt contain data shown in Figure 6, and file Fig7.txt contain data for Figure 7.