Select a sentence from the body of this article that can be removed without affecting the author's explanation. place the sentence in quotes and explain why it is an unnecessary detail. better farming methods and tools in the 1800s increased food production.
americans were able to grow enough food for their families as well as
to sell. the abundance caused food prices to fall.

the expansion of cotton and the growth of textile factories in northern
states produce the first wave of american industry. more people
turned to work in northern factories as a way to support their families.
thousands of immigrants to the united states also settled in or near
port cities, looking for work. even today, the need for work is a common
reason people move to urban areas.

as a result, cities grew in numbers of people and physical space. as
more people and businesses moved in, they needed buildings for living
and working. they needed ways to move around the city. we call this
process urbanization.

in 1820, the united states had only a few cities of 10,000 residents or
more. about seven percent of u. s. residents lived in urban areas. the
number of cities with more than 10,000 people grew quickly over the next
40 years, especially in the northeast and midwest. by 1860, about 20
percent lived in cities. philadelphia and new york city were the most
populated cities in 1860 and would soon reach one million residents.