Final answer:
The 1976 investigation suggested that the explosion of the USS Maine was likely caused by an internal combustion involving coal dust, not by Spanish intervention or sabotage.
Step-by-step explanation:
The 1976 investigation concluded that the explosion of the USS Maine was likely caused by internal combustion involving the fuel the ship was carrying, as later investigations showed signs that suggested a coal dust explosion. In contrast, the initial 1898 inquiry determined that the cause of the explosion was external, most likely a Spanish mine, as both investigations sought to determine the cause of the tragic explosion which killed over 250 American sailors.
The yellow journalism of the time added to the sensationalism of the event, with newspapers like the New York Journal and the New York World leading the charge with bold headlines and rallying cries such as "Remember Maine, to hell with Spain!", which played a significant role in swaying public opinion in favor of war with Spain.