Strain, who began to focus on Civil War art in the late 1980s, said he uses two- to three-hair brushes and a jeweler's magnifying glass to add nuances to every painting that are difficult to notice with the naked eye. Strain, a Texas resident and a Tennessee native, said an unrelenting attention to detail is the reason most of his paintings are finished in three months.
Strain said that meticulousness also must apply to historical facts to appease the most finicky analysts.
"You really have to be a historian, not just a great artist, because you have to back it up," he said. "People will ask you why you did certain things."
Strain spent nearly four hours signing prints of his latest work, "The Old Railroad Wrecker." The painting depicts an 1862 scene of Jackson and Lt. Col. Turner Ashby planning strategy as Confederate soldiers destroy nearby railroad tracks.
Strain said Jackson was well-known for destroying tracks to the supplies to enemy forces dependent on the routes.
A majority of Strain's works focus on officers from the Confederacy because its military leaders, including Jackson and Gen. Robert E. Lee, were generally more identifiable, vibrant characters.
Strain said focusing on Civil War themes allowed him to include two of his long-standing passions in his profession - painting and history.
"To be able to portray American historical events and bring them to life adds a lot to people's understanding of it," he said. "I think it brings people closer to the characters, like baseball cards do."
Several collectors getting last-minute autographs from Strain said his paintings are, by far, the best Civil War works they have seen.
"They're so vivid and clear that they tell a whole story," said Laurie Rushbrook of Martinsburg, W.Va. Rushbrook has been collecting Strain's works for about three years.
Steve Barnisky of Shepherdstown, W.Va., said he owns prints of 54 of Strain's estimated 60 works and will not part with doubles.
"I'm not trying to buy them up and sell them on eBay. I just like everything he puts out," he said.