Recommended text editors: Notepad++ , TextPad, TextWrangler (for Mac)
TEI Lite: http://www.tei-c.org/release/doc/tei-p5-exemplars/html/tei_lite.doc.html#faces
A transcribed letter fully encoded in XML format TEI: http://nzetc.victoria.ac.nz/tm/scholarly/tei-JCB-001.html
Letter from John Adams to Abigail Adams, 3 May 1789: http://www.masshist.org/digitaladams/archive/doc?id=L17890503ja&rec=sheet&archive=&hi=&numRecs=&query=&queryid=&start=&tag=&num=10&bc=/digitaladams/archive/browse/letters_1789_1796.php
Letter from John Adams to Abigail Adams, 1 May 1789: http://www.masshist.org/digitaladams/archive/doc?id=L17890501ja&rec=sheet&archive=&hi=&numRecs=&query=&queryid=&start=&tag=&num=10&bc=/digitaladams/archive/browse/letters_1789_1796.php
About the transcription of the Adams letters: http://www.masshist.org/digitaladams/archive/about/transdetail.php
Civil War Love Letters: http://www.historyhappenshere.org/archives/7642