of the 1840’s became wider and more dome shaped than those of the 1830’s. By 1842, they needed more support to get the width than you could get piling on many petticoats.
Petticoats began to be stiffened with horsehair woven into fabrics like linens.
(Photos: the widening dome of this 1843 cotton dress is made by the 1843 horsehair predecessor to the crinoline)