Step 1: Early leaders of the Indian National Congress.
The Indian National Congress was established in 1885 and its early phase was dominated by moderate leaders who believed in constitutional methods and dialogue with the British government to achieve reforms.
Step 2: The second session of the Congress.
The second session of the Indian National Congress was held in 1886 at Calcutta. This session was presided over by Dadabhai Naoroji, one of the prominent moderate leaders of the early nationalist movement.
Step 3: Contribution of Dadabhai Naoroji.
Dadabhai Naoroji is often called the Grand Old Man of India. He also developed the famous Drain Theory, which explained how British rule was draining wealth from India to Britain.
Step 4: Conclusion.
Therefore, the early nationalist leader who presided over the second session of the Indian National Congress was Dadabhai Naoroji.
Final Answer: Dadabhai Naoroji.