After a prolonged agitation by a section of Sikh community, East Punjab or the Indian Punjab went through a phase of reorganization in 1966. This reorganization took all the areas, which did not declare Punjabi as their mother tongue, out of Punjab. These included the three Jaat dominated districts of Gurgaon, Rohtak and Hisar plus Mohindergarh, which became the core of the new state of Haryana, some other districts, which included Karnal, Ambala and Jind rightly or wrongly were also included in Haryana.
A sizable population in these districts speaks Punjabi, but because they returned Hindi as their mother language during the previous census held in 1961, they were made a part of Haryana, where Hindi is taught as the primary language. Some areas of Hisar, which prior to 1947 had majority of Muslim population and in 1947 Punjabi refugees both Hindus and Sikhs were settled. These areas called Sirsa, Fatehabad and Dabwali also fell into the share of Haryana.
The district of Kangra, which included Palampur, Dharamshala, Kullu and Manali and at one time included Lahaul and Spiti and Keylong areas, which speak Pahadi dialect of Punjabi language were also merged into the tiny hill state of Himachal Pradesh. Shimla, which was the summer capital of Punjab, was also taken out of Punjab and made a part of Himachal Pradesh.
These days, I am at a small suburb of Shimla called Shoghi or Shogi or Shogie. When I talk to the local folks, I talk in chaste Punjabi and to my utter surprise, they reply back in Punjabi. This proves that this area has not forgotten its roots.