Assam Bengal Railway started construction of a railway track on the eastern side of Bengal in 1891. A 150 kilometres (93 mi) track between Chittagong and Comilla was opened to traffic in 1895. The Comilla-Akhaura-Kalaura-Badarpur section was opened in 1896-1898 and finally extended to Lumding in 1903.The Assam Bengal Railway constructed a branch line to Guwahati, connecting the city to the eastern line in 1900. The line was extended to Tinsukia in 1902 and it was also connected to Dibru-Sadiya Railway in 1903.
(source :- internet, wiki)