"The 'byline,' as newspaper authorship is known, was a legacy of Civil War coverage, historian Brayton Harris said Saturday. Joseph Hooker, a Union general, made reporters 'sign' their stories because of concerns about sensitive military information being printed, Harris said.
Actually, who gets a byline and under what circumstances has been an editorial decision from before the Civil War. Bylines were not invented by military decree. In the course of the early ACW, the pressure brought on reporters by commanders caused writers to make their bylines disappear - for personal safety and to obscure who printed what secret. Consider the origins of AP in 1861:
Reporters in the field, facing censorship challenges, use the anonymous byline “Dispatch to the Associated Press.” Their stories are sent to AP’s Washington, D.C. agent Lawrence Gobright, who telegraphs them to New York.
Hooker therefore restored the byline by compulsion; additionally, some writers, operating under his purview, were bylined though they might not have met their own papers' editorial test for the honor.
(Top right, reporters' CW memorial arch at Crampton's Gap.)