The HGP donor DNA library used far more than the others was RP11, also called RPCI-11.
The publicly funded project created libraries from DNA donated by several volunteers, but the libraries were not equally useful. RP11 offered large, consistent inserts, strong genome coverage, and a well-characterized clone collection. Those practical advantages made it the preferred source for mapping, end sequencing, and selecting BAC clones for the reference assembly.
A survey of the HGP sequence database around 2000 found that roughly 80% of the large-insert clones were from RPCI-11. More broadly, much of the resulting reference genome came from one anonymous male donor associated with the Buffalo, New York, sampling effort. The choice was driven by library quality and availability, not by a claim that one individual represented every human genetic variant.
RP11 is often confused with later reference resources. HG002 is a modern sequencing benchmark sample, CHM13 is the haploid sample used for the Telomere-to-Telomere assembly, and NA12878 is a well-known unrelated reference sample. None was the dominant BAC library of the original public HGP.