Cavalry kept more colour and decoration than any other arm throughout the 19th century. Here is a tour.
Quick answer. 19th century cavalry uniforms preserved the four Napoleonic types (hussar, dragoon, cuirassier, lancer) through the century, with each type developing its characteristic dress. Hussars kept the dolman, pelisse and fur busby. Dragoons kept the long tunic and brass or leather helmet. Cuirassiers kept the cuirass and horsehair crested helmet. Lancers kept the czapka. By 1900 these elaborate uniforms had become ceremonial rather than functional, with cavalry regiments adopting khaki or grey for field service.
Hussars across the century
The hussar uniform of 1812 (short dolman, matching pelisse, Hungarian breeches, Hessian boots, fur busby or shako) remained essentially the same throughout the 19th century. Regimental colours became codified. The British 11th Hussars kept their crimson overalls from the 1840s. The French regiments kept their individual facings. The Prussian Death's Head Hussars kept their black and silver. By 1900 the hussar uniform was the most elaborate cavalry dress in Europe, with each regiment proudly distinct.
Dragoons
Dragoon uniforms evolved more slowly. The long tailed coat of 1812 became a shorter tunic by 1850, with a brass or leather helmet (often with a horsehair crest). British dragoons kept the scarlet tunic. French dragoons wore dark blue. Russian dragoons wore dark green. US dragoons (later cavalry) wore dark blue. The dragoon horse was larger than the hussar's and the uniform less decorated, consistent with the regiment's shock role. By 1900 dragoon regiments were essentially heavy cavalry, with lighter regiments reassigned to the hussar or chasseur categories.
Cuirassiers
The cuirass survived in several European armies through the 19th century. French cuirassiers at the Franco Prussian War in 1870 wore essentially the same brass helmet, cuirass, dark blue coat and buff breeches as Napoleon's cuirassiers in 1812. German cuirassiers wore similar. Russian cuirassiers (including the famous Chevalier Guard) wore white tunics with silver cuirass. The British Household Cavalry kept the cuirass for state ceremonial dress, which survives today. The cuirass was increasingly symbolic rather than defensive: by 1870 it would stop a sabre cut but not a modern rifle bullet.
Lancers
The lancer uniform (czapka and plastron tunic) spread widely in the 19th century, imitating the Polish uhlan pattern. Britain raised five lancer regiments after 1816: the 5th, 9th, 12th, 16th and 17th. France, Austria, Russia, Prussia all kept lancer regiments. The lance itself became obsolete as a weapon after 1870 but the uniform survived until 1914 and beyond. British lancer regiments wore dark blue tunics with regimental plastron colour, dark blue overalls with regimental stripe, and the famous square topped czapka.
Household Cavalry
The British Household Cavalry preserved the most elaborate cavalry dress of the 19th century. Life Guards: scarlet tunic with blue facings, cuirass, brass helmet with white plume. Royal Horse Guards: blue tunic with scarlet facings, cuirass, brass helmet with red plume. The state dress with cuirass was reserved for the most ceremonial occasions. The daily guard dress (without cuirass but with helmet and plume) was worn for everyday ceremonial duties. The Household Cavalry still wears essentially this uniform today, as it has done since the mid 19th century.
The field dress transition
From the 1880s onwards cavalry regiments in colonial service began wearing lighter clothing. Khaki tunics with lighter headwear replaced the full dress for actual campaign. By 1900 most cavalry regiments held both their full dress (for parade) and a khaki service dress (for field). The modern distinction between field and ceremonial began with the 19th century cavalry. By 1914 the German, French and British cavalry were in grey or khaki in the field, with full dress worn only on specific state occasions.
Common questions
Did cavalry really charge in full dress uniform?
Through most of the 19th century, yes. The Charge of the Light Brigade at Balaclava in 1854 was ridden in full dress uniform. By 1900 field dress had replaced full dress for actual combat.
Why did cavalry keep elaborate dress longer than infantry?
Cavalry was considered the senior arm socially and ceremonially. Officers were often aristocrats who could afford more elaborate dress. The arm's prestige depended partly on visible splendour.
When did the cuirass disappear?
From the field by the 1860s to 1870s. For ceremonial, the British Household Cavalry still wears the cuirass today.
What are overalls in cavalry dress?
Tight fitting trousers worn by cavalry over long boots, often with a regimental coloured stripe down the outer seam. The British 11th Hussars wore crimson overalls, the 10th wore red, and so on.
Where can I see 19th century cavalry uniforms?
The Household Cavalry Museum, the National Army Museum and regimental museums across Britain and Europe hold outstanding collections.