  We construct LHC signature footprints for four semi-realistic string/$M$
theory vacua with an MSSM visible sector. We find that they all give rise to
limited regions in LHC signature space, and are qualitatively different from
each other for understandable reasons. We also propose a technique in which
correlations of LHC signatures can be effectively used to distinguish among
these string theory vacua. We expect the technique to be useful for more
general string vacua. We argue that further systematic analysis with this
approach will allow LHC data to disfavor or exclude major ``corners'' of
string/$M$ theory and favor others. The technique can be used with limited
integrated luminosity and improved.
