Federal Census Microfilms and Soundex, available at National Archives, links do not work. Do we have your permission to remove them? Thanks for the great article.
Links that do not work:
1920 T625, Soundex M1550, 1910 T624, Soundex T1260, 1900 T623, Soundex T1034, 1880 T9, Soundex T735, 1870 M593, 1860 M653, 1850 M432, 1840, 1830.