The correct answer to this open question is the following.
After 1863, what most fulfilled the "new birth of freedom" that the excerpt refers to was the ratification of the following amendments to the United States Constitution: the 13th the 14th, and the 15th.
After so many conflicts, the 13th Amendment to the US Constitution officially abolished slavery in the United States in January 1865. Then,
the 14th Amendment was very important because for the forts time it granted citizenship to former African American slaves, as well as equal rights and freedom. Finally, the 15th Amendment was another important step in the conformation of one society in the US, when black men got the right to vote.
The largest city in the United States in the year 1900 was New York City with a population of 3,437,202. The second largest city was Chicago, and third largest was Philadelphia. St. Louis, Mo. followed. Washington DC was the 15th largest city at the time.
The major accomplishments of Charlemagne include developing the rules of the feudal system, encouraging reading and writing throughout his empire, developing commerce with a unified monetary system, and the unification of all Germanic peoples into a single kingdom through his crusades, which sought to convert all subjects to Christianity.