The Port of Kolkata is a riverine port in the city of Kolkata, India, located around 126mi from the sea. It is the oldest operating port in India, and was constructed by the British East India Company.The Port has two distinct dock systems - Kolkata Docks at Kolkata and a deep water dock at Haldia Dock Complex, Haldia.In the 19th century, the Kolkata Port was the premier port in British India. After slavery was abolished in 1833, there was a high demand for laborers on sugar cane plantations in the British Empire. From 1838 to 1917, the British used this port to ship off over half a million Indians from all over India — mostly from the Bhojpuri Belt, Bengal, and Tamil Nadu — and take them to places across the world, such as Mauritius, Guyana, Suriname, Fiji, Belize, and the Caribbean Islands as indentured laborers. This explains the Indian Diaspora reaching as far as South America and the West Indies. There are millions of Indo-Mauritian, Indo-Fijian, Indo-Caribbean, Indo-Guyanese, Indo-Surinamese, and Indo-Belizean people in the world today. After independence, the port's importance decreased because of factors including the Partition of Bengal (1905), reduction in size of the port hinterland, and economic stagnation in eastern India.