If your skin is purple and purple people are not allowed to vote, it's likely your elected officials would not pay much attention to issues that are important to purple people, right? And you wouldn't find purple people in Congress or state legislatures either. OK now change skin color from purple to black. You will see that for many many years, Congress and many state legislatures were mostly (if not entirely) white males.
<span>White men of the 18th and 19th centuries already had their rights and so the civil rights movement as we know it today didn't exist back then. It was only when blacks and women gained the rights to be educated and to vote in the late 1800s and early 1900s that the civil rights movement began to take hold and by the 1960s there was a flood of civil rights legislation being signed into law. You will also note that this happened as more blacks and women got elected to Congress and state legislatures. </span>
Books, and other things etc.
Well, a thesis statement is a short statement, normally one sentence at most, that summarizes the claim or point of your essay, research, etc. And it's developed throughout the writing, with supporting details and such. Normally, I like to word my thesis statements in introductory paragraphs, because that works best, and that's what it is, an introduction. So you could add a little umph to it. For example: "How we behave in public acts as a sort of social glue." And add on from there. Or: "How we act around people, and in general, acts as a magnet, better manners attract people, while bad manners push people away." And add on from there. Also maybe think of some more vivid words to help you. For example, social glue is very eye catching, but it might not be the best word choice. Maybe instead of glue use magnet.