In most states, which public official is next in line if the Governor of a state cannot fulfill his duties?

Was giving by lincoln on march 4, 1865-as lincoln prepared to speak, the civil war was drawing to a close-lincolns address of 703 words was the second shortest inaugural address-lincoln mentions god 14 times-505 of the words were one syllable -he used the word "war" or it's pronoun 9 times

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.