Clays and shales are useful because they can be made plastic by adding
water, formed into desired shapes, and fired to a rock like hardness. As
a result, various kinds of bricks, drain tile, pottery, and other useful
products are made from them. In its early years, Illinois had many
widely distributed potteries that used clay from nearby deposits to make
a variety of jugs, crocks, and bowls that served in place of many
present-day glass or metal articles.
Drain tile has been of major importance in the development of the state.
Early settlers found many low lying, swampy areas and tracts of land
that drained poorly after heavy rains. Ditches were dug to carry away
the water from some areas, but others were drained by means of drain
tile—pieces of fired clay pipe several inches in diameter and about a
foot long that were laid end to end in trenches below plough depth and
then covered with earth. Water seeped into the tile, which discharged it
into ditches. Tile factories, built throughout Illinois near clay or
shale deposits, did an active business. Gradually, however, as more and
more farm land was drained the demand slackened and many tile factories
went out of business. Although there are fewer factories, much drain
tile is still manufactured in Illinois.
Many of the early tile plants also made bricks to be used for making
foundations, buildings, sidewalks, and other structures. The bricks were
made by hand-operated equipment. Some of the old hand-molded bricks may
still be seen in older buildings. Now the brick-making process is highly
mechanized and even though there are fewer plants they produce more
bricks.