An ornate capital O from The Virginians by William Makepeace Thackeray, 1858.

Ornate capitals have physical counterparts.  For example, this is the U of Ulram Chapel as it appeared before 1876.  It is preserved in Holderness and Hullshire Historic Gleanings, 1886.

"Charlie ... gestured with his head to the letter."
—S. L. Richardson, All The Way (2008)

The illustration of the giant letter P is from Punch, 1857.

John Leech sketched this for a tale about a clown who had to crack jokes in a circus while his wife was in her dying agonies after fatally missing her footing on a leap from a standing position on horseback; the rip in the hoop is meant to suggest the initial letter I of the story.  From Cornhill magazine, 1864.

I-eye:  an illustration from Told After Supper by Jerome K. Jerome (1891).

If you ever open a bottle and hear a hissing sound, stand back.  This snaky letter S is from Sunday magazine, 1875.

My dream was concupiscent.

The "Cone of Silence," made famous in the Get Smart comedy series, first appeared over a century earlier, in Punch, 1857.

[For Jonathan.]

An illustration from a 1920 issue of Harper's magazine.  The caption reads: "Dropping their H's."