In 1837 Queen Victoria of England had been crowned and the Industrial Revolution was the dominate force in society. The growth of industry and technology caused some people to become wealthy, while the rest of the population stayed poor. But of course, poor people didn't want to look like they were poor, so they gravitated toward designs that were flowery, luxurious, and flashy.
You can recognize Victorian style by its ornate and cluttered designs. The general belief was that good design and displays of wealth were the same thing. Having a luxuriously designed object meant that you were able to afford it.
With the increased amount and quality of mass produced designs during the Industrial Revolution, luxury items that only the wealthy could afford could now be bought by the masses. So the wealthy needed to increase the ornamental design that went into expensive goods to make them more exclusive.
This lead to a snowball effect, and soon Victorian designs were getting out of control. Cities had to outlaw posters in certain areas because designers and companies were creating so many that they were covering every surface. The early increase in demand caused too many graphic designers to enter the field and over saturated the market with their work. As the style became too commonplace, new and more exclusive styles would gain popularity.