While the rest of the country was reorganised on the linguistic line in the 1950s, why had Punjab to wait till 1966?

After independence, the country was divided into different states on linguistic grounds because of the struggles by the people for linguistic re-ordering. Punjab was inhabited by two linguistic groups: Hindi-speaking people and Punjabi-speaking people. From the late 1950s, Punjabi speaking group stated their demand for a separate state. Akali Dal - the political wing of the Sikhs - had led the movement demanding the separation of the state. But they lacked support from the non-Sikhs and the other group of people. Thus the weakness of the movement delayed its bifurcation till 1966. In 1966, the states Haryana and Himachal Pradesh were formed from Punjab.