1. It is known of him that he married Elizabeth Dingley. (is known of)

2. It was said about her that she had died young, before becoming a bride. (Was said about)

3. He had said of her that she was a fantasist. (Said of her)

4. It is said of the young John Evans that he intended during his lifetime to build a city. (It is said of)

5. This is said of a man in fear. (This is said of)

I'm not sure whether 1,2,3,4,5 are all correct and natural English.

Do you think they're all correct?

fire1Do you think they're all correct?

They are, but they sound like they were written in 1802.