One would be sweet corn.
The biggest cash crop was tabbacco
Syrup?
in the center of town
Corn, beans and squash which were typical Native American fare. Sweet corn is still a major Rhode Island farm crop.
Ornamental, sod and othern greenhouse plants. Sweet corn is their major edible crop.
Greenhouse products and sod.
Today it is greenhouse and ornamentals including sod farms. Sweet Corn is a distant second.
Well, the MAIN crops were sod, and, just for some extra info., they also produced a LOT of cheese.
Rhode Island is very well known for their immense cantaloupe selection. They are also known as the inventor of the pukalupe tree (pu-ka-loop) which much like its sister the pakalupe (paw-ka-loop) it taste like a mix between tree bark and banana pudding. The other crop that Rhode Island is known for growing is the green bean potato plant that is put in most coffees.
The Native American trio of corn, beans and sqush. It took a while to clear till and plant the cereal grains of Europe.
This question seems to speak about US history. In the South, most crop workers were slaves. In the North, farmlands were worked by farm owners and their paid farm workers.
Sweet corn is an edible crop that is readily available but the cash crop comes from the wide variety of ornamentals or greenhouse plants, sod and decorative trees and plants. Truck gardens do well and have a ready urban market.