A Tale of Two Cities is set in the 18th century, during the French Revolution. One of the reasons for that revolution was the vast differences in the living conditions of the rich and the poor. Crops had failed, so there was a shortage of wheat and prices were high. It has been said that Marie-Antoinette was so oblivious to the lifestyles of the poor that when told they couldn't afford to buy bread, she said, "Then let them eat cake."
The poor were underfed, overtaxed, and had few rights. Here is a quotation from the eNotes section on Historical Context:
"Overcrowding, disease, hunger, long hours of work, and mindless, repetitive labor," explains Ruth Glancy in A Tale of Two Cities: Dickens's Revolutionary Novel, "characterized the new life for this new class of urban poor." This underclass was largely scorned or ignored by society. It had no rights, it could not vote in elections, and it could not legally form unions for its own protection. In addition, Glancy states, "many members of the upper classes feared even educating the poor, in case they would then become politically aware and eager to better themselves when it suited many people to have them as cheap labor."
Some adjectives to describe their lives: poor, hungry, malnourished, oppressed, uneducated, disenfranchised, angry!