"Ocean Steam Navigation and the Ocean Post" by Thomas Rainey is a scientific publication written in the mid-19th century. This work delves into the critical role of ocean steam navigation in commerce, communication, and national interests, arguing for the establishment of a robust American steam postal system. It discusses various aspects such as the costs, capabilities, and operational necessities of steam mail vessels compared to traditional sailing ships, highlighting the importance of reliable and fast mail services for the prosperity of the United States. At the start of the work, Rainey presents the compelling arguments that ocean steam mails are essential to the growth of commerce and diplomacy for America. He acknowledges the historical progress and triumphs of steam technology while emphasizing its significance in enhancing communication across long distances. The opening also reveals his intent to provide a comprehensive examination that would assist government officials and stakeholders in understanding the complexities and necessities surrounding transmarine steam navigation, especially in movement of mail. Additionally, he stresses the incumbent dependence of the United States on the British steam mail system, pressing for a national effort to establish American capabilities that can compete on the global stage. (This is an automatically generated summary.)