What is the central idea of “the unspoken history behind a surname”

That there is a hidden meaning behind the last name of African American people in United States that can be tracked back to slavery days.

Explanation:

In “The Unspoken History Behind a Surname”,  writer  Lolly Bowean stated that many of the surname that held by African Americans were actually given during the slavery days.  

In the past, Slave owners wanted to make it easy to identify the slaves that they owned. So they change the name of African Slaves to the name that is common in western hemisphere.

She used her surname as an example. Bowean was a name of a small city where a slave plantation once located. The owner change her ancestor's name to signify that her ancestors belonged to the plantation.

ford’s revolution of the assembly like to make cars less expensive

explanation:

in the 1800s, chinese workers migrated to the united states, first to work in the gold mines, but also to take agricultural jobs, and factory work, especially in the garment industry. chinese immigrants were particularly instrumental in building railroads in the american west, and as chinese laborers grew successful in the united states, a number of them became entrepreneurs in their own right. as the numbers of chinese laborers increased, so did the strength of anti-chinese sentiment among other workers in the american economy. this finally resulted in legislation that aimed to limit future immigration of chinese workers to the united states, and threatened to sour diplomatic relations between the united states and china.