A few years ago a TV special aired with the title “The From Whence We Came Awards.”
I don’t recall what the awards were for. I just remember reacting to the use of “from” with the word “whence.”
“Whence” is not synonymous with “where.”
Whence means “from what place/source/origin.”
The wealthy man never forgot the poverty whence he came.
A stranger appeared in our midst. We know not whence he came.
Whence came these caterpillars?
Clearly, the use of “whence” in modern English is extremely limited. If you choose to use it, remember that the “from” is built in.
Where has the meaning “at what place” or “in what place.”
Unnecessary prepositions also show up with where.
One often hears “Where’s he at?” and “Where’d he go to?” instead of the more grammatical “Where is he?” and “Where did he go?
The unnecessary “to” is not as frequent as the added “at.” Perhaps the contraction of “where is” into “where’s” accounts for the speaker’s need to add the unnecessary “at” for balance.