How did railroads change how mail was delivered?

Railway cars were used to sort mail route. When Railway Mail Service began in 1864, mail was exchanged on nonstop trains by hand. Trains were slowed down so clerks could pass the mail off to one another. Shortly thereafter, this dangerous system was replaced with wooden F-shaped cranes placed trackside.

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.

not sure might be he acquired the entire oregon territory from great britain