Among other interests, it operated the sugar industry in Guyana (British Guiana before independence in 1966), running five Booker Line ships, until it was nationalised around 1970. After six months, Booker was called back to market the sugar. Booker had a long history of exploitation of sugar workers through the indentured labour system during the 19th and 20th centuries (outright slavery was abolished in British Guiana before Booker's founding, but exploitative labour practices continued. All of the Booker brothers had claimed and received 'compensation' payments for their post 1815 Guiana slave holdings - see U.C.L. "Legacies of British Slave-ownership" index).