Plans were made to expand the Szolnok–Debrecen railway line towards Nyíregyháza and Miskolc, but due to the political situations of the time – there was a revolution against Habsburg rule in 1848–49 – construction was delayed until 1857.
Disagreements between the railway constructing company and the local government of the city hindered work.
The station building that stands today was designed by Ferenc Pfaff and was built in 1901 in eclectic style.
During the construction of the building important archaeological findings were made, indicating a Celtic presence in the area.
The square is named in honor of Kálmán Kandó (1869–1931), a Hungarian engineer who developed components for electric locomotives.