The Calcutta port was commissioned on October 17, 1870, under the Calcutta Port Act. It went on to become the most important port in British India.
The port came to be governed by a trust from this day, though port and shipping activities at Calcutta had started almost two centuries earlier, with the arrival of the British, long before the East India Company set up its marine establishment in 1758. Colonel Watson set up a marine yard in 1780 and the first dry dock was set up in 1790, though it closed down in 1808. The River Trust was formed in 1866. In 1870-1871, the six Calcutta jetties were handling 143 vessels with a net tonnage of 2,22,446.
After the abolition of slavery in Britain in 1833, British authorities are said to have transported about two million Indian indentured labourers to its colonies. Most of the labourers left from the Calcutta port.