From the Summary: "Restrictions on travel and remittances to Cuba have constituted a key and often contentious component in U.S. efforts to isolate Cuba's communist government since the early 1960s. Such restrictions are largely part of the Cuban Assets Control Regulations (CACR), the overall embargo regulations administered by the Department of the Treasury's Office of Foreign Assets Control (OFAC), as well as certain parts of the Export Administration Regulations (EAR), administered by the Department of Commerce. Various Administrations have eased and tightened these restrictions over the years as U.S. policy toward Cuba has changed."
CRS Report for Congress, RL31139
Congressional Research Service: https://crsreports.congress.gov/