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1960 U.S. Census Myths and Facts

22 May 2024 4:09 PM | Anonymous

The 1960 U.S. Census is the next census scheduled to be released to the public in the year 2032. That’s only 8 years from now. I certainly am anxious to see those records. A recent discussion has erupted over the preservation of the original data. It reminds me of the controversy about the 1960 U.S. Census.

For years I have heard stories about the 1960 U.S. Census. The stories vary a bit on each telling but usually say something like, “the 1960 U.S. Census was stored on a computer media for which there no longer was any equipment to read it. The census data has been lost because of the change in technology.”

I always doubted that story. I was just starting my career in computers in the late 1960s and early 1970s, and I remember well the tape drives of that era. I spent many hours repairing those half-inch and three-quarter inch tape drives that weighed 800 pounds each! I think I still could disassemble and reassemble a Honeywell 204B-9 half-inch tape drive while blindfolded. That device was a maze of electronics (without integrated circuits), disk brakes, a big vacuum pump, and numerous solenoids. 

Since I am familiar with both the old and the new technologies involved, I decided to investigate the 1960 census story. In fact, David G. Hendricks, a historian at the U.S. Census Department, long ago wrote the true story of what happened. Here is what I learned:

The 1960 census returns were recorded on paper, then microfilmed in 1961 for long-term storage. In addition to the microfilm, the Census Bureau also creates many reports from the information obtained in each census. These reports are mostly demographic in nature. They describe the ethnic make-up of the U.S. population. They also document American migration patterns and even tell how many bathrooms are in the average American home. 

In 1961 the staff at the Bureau of the Census had access to a brand-new electronic behemoth known as a “computer.” In order to simplify some of the data analysis that the Census Bureau must conduct, the staff used the new computer to create the “microaggregation files” that contain statistical information. This information had been entered on punch cards in earlier censuses, but magnetic tape was the storage medium of choice in the sixties. The Bureau of the Census had the required data keypunched and then stored on 9,121 reels of magnetic tape: 7,297 reels created with UNIVAC II-A tape drives; 1,678 tapes created with UNIVAC III-A tape drives, and another 146 magnetic tapes created on still other brands of tape drives. The reports needed were generated and printed on paper. Once the reports were completed, the tapes were placed in storage.

Following consultation with staff of the National Archives in 1975, the Census Bureau created a plan to provide for the "adequate retention of the 1960 data." The plan specified that the Census Bureau would copy only 642 reels of tape onto more modern storage media – at least, modern by 1975 standards. The other reels of tape were deemed to be unimportant and of no long-term value. 

All of the stories about loss of 1960 Census data revolves around the 642 reels of tape readable only by UNIVAC II-A tape drives. By 1975, the UNIVAC II-A tape drives were obsolete. Despite the challenge, the Census staff managed to find some old tape drives still in use that could read the tapes. These old drives were installed on a computer system which also had newer drives installed, so a tape conversion seemed simple. By 1979, the Census Bureau successfully copied 640 of the 642 II-A tapes onto newer-format tapes. The two tapes that were not copied were, in fact, missing. The missing tapes had 7,488 records, or about 0.5 percent of the total of approximately 1.5 million records that had been identified as having long-term value. Of the 640 tapes that were located, only 1,575 records (or less than .2 percent of the total number of valuable records on II-A tapes) could not be copied because of deterioration.

The bottom line is that 99.3% of the 1960 microaggregation data was saved on modern tape formats and can be read today. Every decade or so, the data will again be copied onto modern media of the time. Remember, too, that the findings of the original study had already been published on paper in the 1960s, and that the paper findings are also preserved. 

As mentioned earlier, censuses prior to 1960 had the microaggregation data entered on punch cards. However, those cards were always thrown away after the studies were completed and published (on paper). The loss of 0.7% of the 1960 microaggregation data files on magnetic tape doesn’t seem like such a big loss. That is still 99.3% more data preserved than any earlier census. As historian David G. Hendricks of the U.S. Census Department wrote to me, “these files performed their function, and all of the data are available on paper, if not electronic, form; so none of the information from the 1960 census has been lost.”

All this discussion of magnetic tape really isn’t important to genealogists anyway. All of the microaggregation files on magnetic tape mentioned here did not have any genealogy value since there were no names or street addresses listed. Genealogists should have no fears about “missing data.” The magnetic tapes only stored a subset of the census data, a subset of no interest to genealogists.

The original 1960 U.S. Census documents were recorded on microfilm in 1961, and all that microfilm is still in good condition, locked up at the National Archives. In other words, images of the original documents have been preserved. Admittedly, very few people have seen these microfilms so the genealogy public dors not know if they are still readable or not.

In compliance with U.S. laws, the complete 1960 U.S. Census documents on microfilm will be released to the public in the year 2032, 72 years after the original enumeration. I hope to be around to read those films!

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