Why did workers begin to organize into labor unions in the mid-1800s?

They thought unions would put more people to work in factories.

They were tired of working in isolation at boring jobs.

They wanted safer working conditions and shorter workdays.

They believed unions were the only way to become better at their jobs.

They wanted safer working conditions and shorter workdays.

Explanation:

Around the middle of the 19th century, workers started organizing themselves in labor unions in the hope to solve the problems that arose with the Industrial Revolution.

The main issues that they fought for were

solving the economical problems - fighting against low wages and underpaid jobs; as industry was taking over, workers were starting to be put in the back compared to technology and machines, so the labor force was often underpaid safe working conditions - the injures in factories and other manual labor places were quite common, and workers wanted to make sure they had safe condition in which to work shorter workdays - the workdays before Industrial revolution could go from 10 to even 16 hours, and usually 6 days in a week were workdays. Only in 1817. workers started fighting for the 8-hour workday as we know it today under the slogan "Eight hours' labour, Eight hours' recreation, Eight hours' rest"

Answer:they wanted safer conditions