Ch. 19.4 explain the response to laissez-faire economics during the nineteenth century

The response was that the government should not interfere with the market since it would ensure the prosperity of everyone in the long run. 

The 19th century was known for government wanting to meddle in the affairs of the market because the second half of the century, after the civil war, marked the beginning of the reconstruction and the beginnings of the progressive age when the government wanted to meddle in the market and protect the workers who unionized more and more.