Does a noun clause as a subject sound natural in modern days?

President Lincoln wrote, "That I once had the confidence of the people in Sangamon, is sufficiently evident."

Is this type of sentence construct common in today's English usage?

Solution 1:

"That I once had the confidence of the people in Sangamon" is a content clause. Content clauses are noun clauses. They are considered formal or old-fashioned when used as a subject.

However content clauses are commoner as objects/complements and relative clauses and, today, a person would say either

1 "It is sufficiently evident that I once had the confidence of the people in Sangamon."

or

2. "The fact that I once had the confidence of the people in Sangamon is sufficiently evident."

You will see why "That I once had the confidence of the people in Sangamon" is called a content clause, as it gives the content of the dummy/preparatory "it" and the periphrastic "the fact".

See https://en.wikipedia.org/wiki/Content_clause