"Dr. John W. Heron...was appointed as the first protestant medical missionary to Korea...The source book not only includes valuable personal letters reflecting true stories of the time, but also contains letters from other missionary workers, materials within and out of Korea, directory, census from various regions and countries, number of newsletters, annual report of mission works, books, diplomatic records, immigrant records, public documentation, school records, [and] medical records.--From author's preface, page 7.