The frock coat was originally a country garment, worn by gentlemen for riding and relaxed town wear. Here is the Georgian form.
Quick answer. The 18th century frock coat was a loose cut long tailed single breasted coat with a small turned down collar, deep cuffs, four to eight large buttons, and plain pockets. Worn as country or informal daytime dress by the English gentry from the 1720s onwards, it became an American favourite and spread through Europe. The Victorian version is a slimmer, more fitted descendant with a waist seam, which the Georgian pattern does not have.
Origin and name
The word frock originally meant a loose working garment. By the 1720s English country gentlemen were wearing a looser cut version of the formal coat, calling it a frock coat to distinguish it from the stiff full dress coat (habit a la francaise). The frock coat was for riding, country visits and informal town wear. It did not go to court or to a ball. It was comfortable, simple and increasingly fashionable.
By 1770 the frock coat was acceptable for most daytime occasions short of court. In the American colonies it became more or less universal. By 1800 the formal full dress coat had died out, and the frock coat was the standard men's coat throughout the English speaking world.
The cut
The 18th century frock coat is loose through the body with no shaping at the waist. The skirt flares slightly from the hip and reaches to mid thigh or just above the knee. The front closes with a row of buttons, usually not fastened above the chest. The collar is small and turned down, more like a modern shirt collar than the standing collar of the Victorian era. The cuffs are deep (sometimes 6 inches or more) and often turned back to show the lining.
Pockets are set low, usually with large flaps. Decoration is restrained: a line of lace or braid at the cuff and collar, matching buttonholes. The whole look is more relaxed than the stiff formal dress of the court or the elaborate military patterns.
Fabric and colour
Georgian frock coats were made in wool broadcloth, worsted or cotton for summer. Colour varied widely by period and region. Earlier in the century, muted shades of brown, olive, green and plum predominated. Later in the century, darker shades of blue, charcoal and black became fashionable. The country gentleman's frock coat was often undyed or lightly dyed to look like homespun. The town version was finer wool and a more fashionable colour.
In America
The frock coat became the standard American gentleman's coat during the Revolutionary and early Republic periods. George Washington wore frock coats throughout his civilian life. Thomas Jefferson's portraits by Rembrandt Peale and others show him in various frock coats, usually in a plain dark colour. The American frock coat was less decorated than the English, consistent with Republican dress sense. By 1800 the frock coat in America had displaced older formal coats almost entirely.
Transition to the Victorian pattern
The transition from the loose Georgian frock coat to the fitted Victorian version happened gradually between about 1810 and 1840. The waist seam was introduced to allow a more tailored body. The skirt became straighter and less flared. The collar grew taller and more structured. By 1840 the modern frock coat silhouette was established. The 18th century version survived longer in rural America and in some older European contexts, but was essentially gone by 1860.
Common questions
Did George Washington wear a frock coat?
Yes, throughout his civilian life. He also wore military frock coats of a more fitted cut as commander of the Continental Army.
What is the difference between an 18th and 19th century frock coat?
The 18th century version is looser through the body, has a small turned down collar and no waist seam. The 19th century version is more fitted, has a tall standing collar and a horizontal waist seam.
What did a Georgian gentleman wear with his frock coat?
A long waistcoat, knee breeches, stockings, shoes or riding boots, and a tricorne hat. In later Georgian wear, trousers replaced breeches and a round hat replaced the tricorne.
Can I buy an 18th century frock coat?
Yes. Reenactor and theatrical tailors build Georgian frock coats in wool broadcloth with hand sewn details. Expect six to twelve weeks of lead time.
Is a frock coat still fashionable?
Not as everyday wear, but it works beautifully for weddings, theatrical performances and formal costume. The modern cut is a direct descendant of the Victorian pattern rather than the Georgian.