Short answers, pulled from the story.
Surnames in England are generally traced to the preparation of the Domesday Book in 1086, following the Norman Conquest. The feudal nobility adopted them first, and by around 1400 most English families had hereditary surnames.
Smith is the most common American surname, carried by about 1% of the population. In total, just 1,712 surnames account for half of all Americans.
Silva is by far the most common surname in both Brazil and Portugal. In Brazil, 34,030,104 people carry it, representing 16.76% of the total population analysed.
Placing the family name first is the Eastern naming convention, followed in Greater China, Korea, Japan, Vietnam, Cambodia, and other cultures. When writing names in the Latin alphabet, people from these traditions often reverse the order so Westerners can identify the family name.
Lucy Stone was the first known instance in the United States of a woman insisting on keeping her birth name, which she did in 1855.
Wang, Zhang, and Li are the most frequent surnames in China. According to some estimates, 85% of China's population shares just 100 surnames.