Every American state has a law requiring certain contracts to be in writing and signed. The rule goes back to an English act of 1677. It was meant to prevent fraudulent claims that would otherwise be “upheld by perjury.”
Typical cases are contracts for land, contracts that cannot be completed within one year, and promises to pay someone else’s debt. For goods, the Uniform Commercial Code adds a threshold. A contract for the sale of goods “for the price of $500 or more” is generally not enforceable without a signed record.