Rowland Macdonald Stephenson (later Sir Rowland, but familiarly known as Macdonald Stephenson[2]) and three assistants travelled from England in 1845 and "with diligence and discretion" surveyed, statistically studied and costed the potential traffic for a railway route from Calcutta (the then commercial capital of India) to Delhi via Mirzapur.

A contract was signed between the East India Company and the East Indian Railway Company on 17 August 1849, entitling the latter to construct and operate an "experimental" line between Calcutta and Rajmahal, 161 km (100 miles) long at an estimated cost of £1 million which would be later extended to Delhi via Mirzapur.

[4] On 7 May 1850, the East Indian Railway Company's managing director Macdonald Stephenson, George Turnbull, the company's Chief Engineer, and the engineer Slater made an initial survey from Howrah (across the River Hooghly from Calcutta) to Burdwan on the route to the Raniganj coalfields.

Bamboo towers 80 feet (24 m) tall were then built above the palm trees at Serampore and Balli Khal to set out the line.

Brick availability became a major problem, so the decision was made to use vast quantities of ironwork – imported from England as India had no iron works at that time.

In late 1859, a horrific cholera epidemic in the Rajmahal district killed some 4000 labourers and many of the British engineers.

[18] On 5 February 1863, a special train from Howrah took George Turnbull, the Viceroy Lord Elgin, Lt Governor Sir Cecil Beadon and others over two days to Benares inspecting the line on the way.

[20] In Benares there was a durbar on 7 February to celebrate the building of the railway and particularly the bridging of the Son river, the largest tributary of the Ganges.

Some historians like Irfan Habib argue that because the contracts signed between East India Company and EIR in 1849 guaranteed 5% return on all capital invested, initially there was no inducement for economy or for employing Indians instead of high-paid Europeans (but initially, there were only experienced British railway civil engineers and no Indian ones).

EIR was stated in 1867 to have spent as much as Rs 300,000 on each mile of railway, the construction described by a former Finance Member in India as the most extravagant works ever undertaken.

In 1860, the Kanpur-Etawah section was opened to traffic, and between 1862 and 1866 all gaps between Howrah and Delhi were filled, and the connection to Agra built.