In May 1964, the passing of Prime Minister Jawaharlal Nehru occurred, following a period of declining health that had spanned over a year. This circumstance triggered widespread speculation about the imminent question of succession: who would assume leadership after Nehru?
Furthermore, there lingered doubts regarding the ability of the forthcoming leadership to adeptly address the array of looming challenges that awaited solutions. The 1960s acquired the moniker of the 'dangerous decade' due to the presence of unresolved issues such as poverty, inequality, communal tensions, and regional divisions, among others. These concerns loomed large, potentially jeopardizing the trajectory of the democratic endeavour or even the unity of the nation itself.

Why had Lal Bahadur Shastri resigned from the position of Railway Minister earlier?

He accepted moral responsibility for a major railway accident.

The succession following Nehru's passing defied critics' expectations with its smooth execution. After Nehru's demise, K. Kamraj, the president of the Congress party, engaged in consultations with party leaders and members of Parliament. These discussions yielded a consensus in favor of Lal Bahadur Shastri. In a unanimous decision, Shastri was chosen as the leader of the Congress parliamentary party, consequently ascending to the role of the country's next Prime Minister.

Lal Bahadur Shastri, hailing from Uttar Pradesh, emerged as a non-controversial leader who had served as a Minister in Nehru's cabinet for an extended period. Nehru had grown reliant on him, particularly in his final year. Shastri's reputation was grounded in his simplicity and unwavering commitment to principles. Prior to this, he had tendered his resignation as the Railway Minister, accepting moral responsibility for a significant railway accident.