Statutes are laws made by legislative bodies and distinguished from case law which is decided by courts, and regulations issued by government agencies. Statutory laws are made at both the both the state and the Federal levels and are put into practice differently depending on how the executive enacts the laws and the judiciary interprets them.
While laws pertaining to the particulars of slavery were left to the states, federal law governed many issues relating to the international slave trade, the status of slavery across state boundaries (the Fugitive Slave Laws, for example), and the status of slavery in teritories.