"I" is for indigo. Indigo, a plant that produces a blue dye was an important part of 18th century South Carolina's economy. It was grown commercially from 1747 till 1800 and was second only to rice in export value. Eliza Lucas Pinckney experimented with its cultivation in the 1730s and 1740s. In 1749 Parliament placed a bounty of six pence per pound on the dye.
Indigo was grown on lands not suited to rice cultivation and thus fit nicely into the existing agricultural economy. By the eve of the Revolution, the colony exported more than one million pounds of dye. After the Revolution, the loss of the bounty, competition from other sources, and a reputation for a less-than-top quality product destroyed the crop's export market. By 1802, indigo was no longer listed among Carolina's exports.