Hessian refers to a style of boot

Boot

A boot is a type of footwear but they are not shoes. Most boots mainly cover the foot and the ankle and extend up the leg, sometimes as far as the knee or even the hip. Most boots have a heel that is clearly distinguishable from the rest of the sole, even if the two are made of one piece....

 that became popular in the 18th century. Initially used as standard issue footwear for the military, especially officers, it would become widely worn by civilians as well. The boots had a low heel, and a semi-pointed toe that made them practical for mounted troops as they allowed easy use of stirrups. They reached to the knee and had a decorative tassel at the top of each shaft.
The Hessian boot would evolve into the rubber work boots known as "wellies

Wellington boot

The Wellington boot, also known as rubber-boots, wellies, wellingtons, topboots, billy-boots, gumboots, gummies, barnboots, wellieboots, muckboots, sheepboots, shitkickers, or rainboots are a type of boot based upon leather Hessian boots...

" and the cowboy boot

Cowboy boot

Cowboy boots refer to a specific style of riding boot, historically worn by cowboys. They have a Cuban heel, rounded to pointed toe, high shaft, and, traditionally, no lacing...

.

When describing the appearance of Marley's Ghost

Jacob Marley

Jacob Marley is a fictional character who appears in Charles Dickens' 1843 novella A Christmas Carol.- Relationship with Scrooge:In life, Marley was the business partner of Ebenezer Scrooge. As teenagers, both men had been apprenticed in business and met as clerks in another business...

 in A Christmas Carol

A Christmas Carol

A Christmas Carol is a novella by English author Charles Dickens first published by Chapman & Hall on 17 December 1843. The story tells of sour and stingy Ebenezer Scrooge's ideological, ethical, and emotional transformation after the supernatural visits of Jacob Marley and the Ghosts of...

, Charles Dickens

Charles Dickens

Charles John Huffam Dickens was an English novelist, generally considered the greatest of the Victorian period. Dickens enjoyed a wider popularity and fame than had any previous author during his lifetime, and he remains popular, having been responsible for some of English literature's most iconic...

 mentions the tassels on his boots, indicating that they were Hessian style. In Chapter 3 of Thackery's Vanity Fair, in a scene set in England during the Napoleonic Wars

Napoleonic Wars

The Napoleonic Wars were a series of wars declared against Napoleon's French Empire by opposing coalitions that ran from 1803 to 1815. As a continuation of the wars sparked by the French Revolution of 1789, they revolutionised European armies and played out on an unprecedented scale, mainly due to...

, Joseph Sedley is described as wearing Hessian boots.

In the Gilbert and Sullivan

Gilbert and Sullivan

Gilbert and Sullivan refers to the Victorian-era theatrical partnership of the librettist W. S. Gilbert and the composer Arthur Sullivan . The two men collaborated on fourteen comic operas between 1871 and 1896, of which H.M.S...

 operetta Patience

Patience (opera)

Patience; or, Bunthorne's Bride, is a comic opera in two acts with music by Arthur Sullivan and libretto by W. S. Gilbert. First performed at the Opera Comique, London, on 23 April 1881, it moved to the 1,292-seat Savoy Theatre on 10 October 1881, where it was the first theatrical production in the...

, Colonel Calverley sings a song about the military uniform, how impressive it looks, and the effect it has on women. The song specifically mentions Hessian boots:

When I first put this uniform on,

I said, as I looked in the glass,

"It's one to a million

That any civilian

My figure and form will surpass.

Gold lace has a charm for the fair,

And I've plenty of that, and to spare,

While a lover's professions,

When uttered in Hessians,

Are eloquent everywhere!"

A fact that I counted upon,

When I first put this uniform on!