About a century of time: all those years starting with 18, 1800-1899. A trifle different than nineteenth century, which is 1801-1901.
Often confounded with "Victorian," which is the period 1840-1901 when Victoria was Queen of England, which had several subordinate periods of fashion, technology, and culture (as a rational person ought to expect from 60 years). The 1800s included such political eras as the Napoleonic period (he became First Consul in 1802),
the Regency (English rule by the Prince Regent, 1811-1821), the Second Empire in France, the Civil War/War Between the States, the Crimean War, the
Franco-Prussian War, &c. Many schools of art date from the 1800s, such as the Impressionists. Music advanced from the relatively dispassionate intellectuality of the Baroque into the greater
emotionality of Classical music (say, Beethoven), the Romantic composers like
Liszt, the Impressionists like
Debussy, to the
full-bore multi-media entertainment of Wagner.
It also has a strong crossover with the Steam Age, of technology powered by indirect use of energy, fire creating mechanical movement, leading eventually to the harnessing of electricity, the expansion of communication in the telegraph and telephone and the beginnings of electronics in Tesla's radio.