Complex sentence: In 1947, when India became independent, a popular vote rejected Sikkim's joining the Indian Union, although a treaty was made between India and Sikkim in 1950, in the interest of Prime Minister Jawaharlal Nehru.
Split into simpler sentences: In 1947, when India became independent, a popular vote rejected Sikkim's joining the Indian Union. Afterward, a treaty was made between India and Sikkim in 1950, in the interest of Prime Minister Jawaharlal Nehru.