The function PROPER() does exactly that, it transforms "THIS IS MY EXCEL
BOOK" into "This Is My Excel Book".

Eric wrote:
I have multiple Excel spreadsheets containing data that is all upper case. I
would like to modify the documents so that the only the first letter of each
word is upper case and the rest are lower. There is a substantial amount of
data, so manually performing this process would be extremely time consuming.
Is there a way to use formulas to accomplish this automatically?

Thanks!