‘Tis a lesson you should heed,
Try, try again;
If at first you don’t succeed,
Try, try again.

(Other Authors and Sources)

T. H. Palmer, “Try, Try Again,” The Teacher’s Manual (1840)
    (Source)

Sometimes attributed to Charles Theodore Hart Palmer (1827-1897), but the book is clearly by Thomas H. Palmer, and was published in 1840 when Charles T. H. Palmer was 13 years old.