This chapter discusses the development of commerce, labor, and tax laws in the second half of the nineteenth century. It covers contracts, negotiable instruments, the law of sales, usury laws, insurance, bankruptcy, admiralty, labor and law, federal taxation, state and local tax, and death taxes. The law of contract occupies a special place in American law in the nineteenth century. The dominance of contract was one of the sovereign notions of the nineteenth century. By constitutional mandate, no state could “impair” the obligation of contracts. Contract law was also one of the basic building blocks of legal study.