cross a letter - to write over and at right angles (136)
I notice you have acquired the very annoying habit of crossing your letters, which in these days of cheap postage and paper is very abominable. If you cross anymore of your letters to me I will neither read or answer them (Sept. 25, 1859 R. Goelet, Washington)
Tarheel Talk - by Norman E. Eliason
I was reminded of the quote above when I published the post about being ill last Saturday. I'd say he was most defiantly ill about the crossed letters he was receiving.