Proposals for chemical weapons that arose during the American Civil War are described. Most incendiary and all biological agents are excluded. The described proposals appeared primarily in periodicals or letters to government officials on both sides. The weapons were usually meant to temporarily disable enemy combatants, but some might have been lethal, and Civil War caregivers were ill-prepared to deal with the weapons' effects. Evidently, none of the proposed weapons were used. In only one instance was use against civilians mentioned. Among the agents most commonly proposed were cayenne pepper or other plant-based irritants such as black pepper, snuff, mustard, and veratria. Other suggested agents included chloroform, chlorine, hydrogen cyanide, arsenic compounds, sulfur, and acids. Proponents usually suggested that the chemicals be included in explosive artillery projectiles. Less commonly proposed vehicles of delivery included fire engines, kites, and manned balloons. Some of the proposed weapons have modern counterparts.