Over fifty years after his assassination, there still hovers over Nigeria, a picture that leaves within the horizon the impression that the regime of the first Military Head of State in Nigeria was boring and unproductive. Similarly, there is a seemingly maliciously propagated impression that the Supreme Military Council under General Ironsi had no clear-cut agenda and policy for the economically disarticulated Nigeria in 1966. Contrary to these, researches have revealed that General Ironsi’s regime laid a good foundation for not only the peaceful coexistence of Nigerians, but also for the economic, political and diplomatic progress of the country. Using mostly primary and secondary sources of historical data, this study undertakes a post-mortem assessment of General Ironsi’s contributions to nation building efforts and concludes that, if properly followed, General Ironsi’s policies and achievements in the political and economic sectors in Nigeria were to serve as stimulants, as well as springboards for successive military and democratic leaders in Nigeria. Unfortunately, the obvious culture of discontinuation of policies by successive African leaders exerted ugly consequences on Nigerian citizens whose socio-political conditions became worse than it was between January and July 1966. The General’s sincere effort to create an integrated and unified nation laid the foundation for other laudable political, economic and diplomatic reforms of the regime and in turn, created a background for understanding the propitious implications of the recent call for a restructured Nigeria.