an action for the breach of a simple contract (express or implied), which was not under seal. It was used in a wide variety of situations. Plaintiffs used the action of Assumpsit to collect promissory notes, to recover money obtained through Fraud or misrepresentation, to recover damages for the breach of a marriage contract, to recover damages for a failure to deliver merchandise, and in a variety of other situations. A form of Trespass on the Case, Assumpsit was the most commonly used common law action in antebellum Illinois. Assumpsit replaced and was virtually synonymous with Trespass on the Case on Promises. Assumpsit differed from Debt in the nature of the award possible. A plaintiff sued in an action of Assumpsit to collect damages, so the amount of the debt could be uncertain and determined by the court or the jury. In the case of a Promissory Note, the plaintiff sued in an action of Assumpsit to collect damages for the defendant’s failure to pay the debt. The award could include the value of the note, interest, and additional damages that the plaintiff sustained. A plaintiff sued in an action of Debt to collect a “sum certain” or a specific amount. In the case of a promissory note, the plaintiff sued in an action of Debt to collect only the amount of the note and interest.