Each of the clue answers is the common link between its three clues.
When you transfer these to the grid, at first it doesn't seem to spell anything.
OU TERIT WN OKARLI TBIF R FRYHH LHNIAAUS TEZYE OOHE TTICI ORT UB NW AEAAG IL YHXSTLDGOHST TOODBHM RSST L I ELNRB AHEH REETENAA S UESA UAA H OTADKIT DEPWFI JI CDS PSILROTE RHS PH RH GNCETRHASL R SHR NU YTIW NHELMROEW IHWFUEARIPO AE OTEAIATR SKE OC MOB TTHND
It is actually read vertically, starting by reading up the first column and alternating up and down the columns. It says "ON JULY FOURTH EIGHTEEN SIXTY THIS ACCLAIMED ETCHER ILLUSTRATOR AND LITHOGRAPHER WAS BORN. WITH HIS SKILL AS AN AUTHOR HE WROTE BOOKS THAT FOCUSED ON ARTWORK. HE MARRIED ELIZABETH ROBINS. THEY TEAMED UP TO PEN A BIOGRAPHY THAT WAS OF HIS FRIEND WHISTLER." The acrostic in the answers is THIS GUY IS NAMED JOSEPH WHO?
Wikipedia says he was born July 4, 1857, but some sources say Joseph PENNELL was born July 4, 1860. The answer is PENNELL.