If you need a map of baselines and meridians within the United States, there's a good one here: http://www.glorecords.blm.gov/Visitors/PrincipleMeridiansAndBaselines.html
and if you don't know what base lines and meridians are for, take a look at the Bureau of Land Management website. Baselines and meridians are used to describe ruralproperty in those states where land was initially transferrred to private ownership by the federal government insetad of the individual colonies.
Those of you who only have urban ancestors or east coast ancestors might not need these links....
