This is readily explained by the geophysical creation of this kind of rock. As the oceans swirled about hundreds of millions of years past, the basic material sank and was compacted beneath millions of tons of pressure from the seas above. When the oceans receded, creating continents, the various land masses contained veins, or strata, of these two stones. The generally accepted timetable for the formation of these stones is roughly 175 million years, beginning approximately 425 million years ago. The materials from the mountains in the eastern United States spread far and wide, with sandstone forming from central Georgia to upstate New York.
Limestone appears as far west as the Mississippi River in thick sheets in many more places.
This was an area covered by the inland sea. The natural beds of sandstone and limestone are almost always fragmented into pieces, as thermal changes or seismic vibrations broke them into pieces. This was a boon to quarriers, who found little difficulty separating slabs of the stone from the vein of rock. While the calcite found in limestone produces only various shades of white or off-white, sandstone is not bound by this color. Other materials encased in the silica render sandstone a wide variety of colors, and some are quite striking.