The principal message of the cartoon is that the standard oil company

If you are referring to the cartoon that shows the Standard Oil Company as an octopus, then the message is that Standard Oil Company is a dangerous monopoly that controls the US government.

If you look in the picture, you can see that the octopus (representing Standard Oil Company) has its tentacles wrapped around different federal buildings including the State capitol, Congress, and is soon to be taking control of the White House. This symbolism is trying to show that this company has controll over the federal government and that it cannot be stopped. This author is definitely painting the Standard Oil Company in a negative light.

the enslaved people onboard suffered from illness with some frequency

la segunda guerra mundial comenzó el 1 de septiembre de 1939 y terminó el 2 de septiembre de 1945. ¡espero que esto ayude!