PLZ I NEED HELP! Analyze the effects of three inventions on American life between 1865 and 1914. Support your main ideas with facts and/or examples.

A stop sign is a traffic sign, usually erected at road junctions such as a four-way intersection, that instructs drivers to stop and then to proceed only if the way ahead is clear. The idea of placing stop signs at road junctions was first conceived in 1890 when William Phelps Eno of Saugatuck, Connecticut proposed and devised the first set of traffic laws in an article published in Rider and Driver. However, the first use of stop signs did not appear until 1915 when officials in Detroit, Michigan installed a stop sign with black letters on a white background. Throughout the years and with many alterations made to the stop sign, the current version with white block-lettering on a red background that is used in the United States as well as emulated in many other countries around the world today

The answer is b.african american abolitionists emphasized legal and social equality