The origins of this phrase are uncertain, but it has been observed in print since at least 1889, and likely was around well before that. The potentially related phrase "to a tittle" is found in a 1607 play, The Woman Hater by Francis Beaumont and John Fletcher ("I'll quote him to a tittle"). The T in the phrase to a T is likely the first letter of a word, with tittle being the most likely source.
- Other theories with little evidence point to golf tees, for their small size; this may have at least influenced the alternate form to a tee. Some speculate a relationship with T-square, a measuring device introduced around the turn of the century. Others claim the expression refers to the correct completion of the letter t by crossing it.
- (idiomatic) Precisely; exactly; perfectly; with great attention to detail.
- The announcement of the political endorsement was timed to a T.
- 1868, Ann Sophia Stephens, Doubly False
- That accounts for my having the dress, but it don't account for the piece that you left sticking to the rose-bush under Mrs. Lander's bed-room winder, which piece I took off that morning, and which piece I matched with the dress after you pitched it at me over them bannisters; it was an awful scragly tear, and it fitted to a T.