BanglaCapsule | Bangladesh History on  Apr 13

1974 After USA established diplomatic relations with newly independent Bangladesh with Herbert D. Spivack as Chargé d’Affaires ad interim. The first Ambassador Extraordinary and Plenipotentiary was Davis Eugene Boster, who presented his credentials on this day.
Google | Bangladesh USA Relations Timeline
1983 Sramik Karmachari Oikya Parishad (SKOP), the mainstream trade union movement in the country established in a joint meeting of the top leaders of 12 national trade unions in Dhaka.
Google | Sramik Karmachari Oikya Parishad Timeline