Answer
What is the "unfinished work" Lincoln mentions in paragraph 3? Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.
Hello! There are three commonly used rules when writing out numbers in literature.
The first one is numbers under "10" are written out as words (i.e 1-> one, 2-> two, 3-> three, ect)
The second one is if the number is representing a date, you write it in numerical form (i.e years stay in their number-forms)
The final rule is the one that applies for you is that if the number is the first word of the sentence, then you write it as a word instead of it's numerical form.
So the correct way you'd write your sentence is, "Twenty-six people posted messages to my blog in just thirty minutes."
b Richard staying under the tarpaulin