Why Was Title Case Invented?

What problem does Title Case exist to solve?

Well title case was probably introduced for, well, titles. I wouldn’t use it anywhere else.

It is a solution to the problem of:

“How do I get my title to stand out, maintaining maximum readability and conveying the information as effectively as possible?”

So its basis is psychology or perception, and it is as relevant to the modern world and to electronic media as it was to the 19th century.

What is title case?

Capitalizing only important title words, e.g. those other than articles, conjunctions and prepositions. Taking examples from book covers:

The Struggle for Mastery in Europe: 1848-1918

However, what not to capitalize can be somewhat subjective. That is not unnatural, as the principle is to emphasize what is important, and that can be subjective. Here the preposition “before” is capitalized:

Two Years Before the Mast

whereas here the verb construction “would be” is not, although the pronoun “Who” is:

The Man Who would be King

What is not title case?

Two Years Before The Mast

i.e. what you get with the ‘Title Case’ option in MS Word.

However

As many titles are set in upper case, it is not relevant there.

Nachwort

The use of title case may feasibly have been influenced by the German orthographic rule of capitalizing nouns. However I am unaware of any evidence for that.