If you are interested in Orrs in Co. Antrim I can recommend Donald Harman Akenson & W.H. Crawford "Local Poets and Social History: James Orr, Bard of Ballycarry", published in 1977 by PRONI.
James Orr was born in 1770 at Broad Island, Co. Antrim, and was a United Irishman as well as a folk-poet, writing his poems in broad Ulster Scots dialect. After the events of 1798 he escaped to America but returned to Ireland after an amnesty was declared. He settled at Ballycarry in Templecorran parish, Co. Antrim, and devoted the rest of his short life to writing poetry and drinking.
It's thought that Orr's parents were David Orr and Jane Catherwood of Broad Island, and if that's the case, James Orr fits into the Orr Pedigrees, a massive handwritten MS of Orr family-trees, mainly in Co. Down but also Antrim, which is kept in the Linen Hall library in Belfast. The MS was turned into a privately printed book by an American genealogist called Ray A. Jones and I have a copy.
James Orr of Ballycarry looks like a 4th cousin of my 3 x great-grandfather Archibald Petticrew, an Orr descendant who became a joiner in Belfast.
I don't know if William Orr who is the subject of this thread fits into the above-mentioned extended Orr family-tree, but I'd be surprised if he doesn't.
Harry