In the passage from five weeks in a balloon what is the effect of paragraph 13

The italicized sentence is the thesis for the "Influence of Lincoln". This sentence sums up Addam's idea of the piece and the idea that Lincoln was a remarkable person (which he is). Addam's thesis sentence describes Lincoln with wisdom and high motives. The sentence indicates the point that Lincoln was an extraordinary man. No ordinary man has the power to make a huge impact on society, which is why Lincoln was as strong as he was. The above sentence may not be a thesis, however, since it's embedded within one of many stories in the chapter. Usually, a thesis is placed toward the beginning of an essay to summarize the main points to help the reader understand what the piece will be about.