On 20 April 2016, the Facebook page The Common Sense Conservative published an image macro identifying African-American abolitionist Harriet Tubman as a "gun-toting, Democrat-shooting" Republican:
The text included in the macro was vaguely rooted in truth: Tubman reportedly carried a gun during her trips on the Underground Railroad. But it's unlikely she was using a gun to "shoot Democrats" (other than in the vague sense that if someone threatened her efforts to the point of requiring an armed response, that opponent was probably more likely to be a Democrat than a Republican given the alignments of the major political parties at the time).
According to a PBS biography of the abolitionist, Tubman used her gun to threaten the fugitives who grew tired or afraid on their journey to the north (people who were unlikely to be Democrats, given that slaves weren't able to vote at all, and runaway slaves certainly wouldn't have been Democratic Party members even if they could):
Tubman returned to the South again and again. She devised clever techniques that helped make her "forays" successful, including using the master's horse and buggy for the first leg of the journey; leaving on a Saturday night, since runaway notices couldn't be placed in newspapers until Monday morning; turning about and heading south if she encountered possible slave hunters; and carrying a drug to use on a baby if its crying might put the fugitives in danger. Tubman even carried a gun which she used to threaten the fugitives if they became too tired or decided to turn back, telling them, "You'll be free or die."
The assertion that Tubman was a Republican is also something of a stretch. While Tubman fought against slavery and political oppression and thus would have been more politically aligned with the Republican Party platform, she couldn't actually vote (since women's suffrage legislation had been passed in only a few states prior to her death).
Regardless, the biggest piece of misinformation included in this image macro is the photograph. The woman pictured is not abolitionist Harriet Tubman but rather Mary Fields, also known as Stagecoach Mary, the first African-American mail carrier employed by the United States Post Office:
Born as a slave in Tennessee, Fields was one of the first women entrepreneurs, stagecoach drivers, pioneers of the American West. Orphaned as a child, she grew up with Ursuline nuns but received no formal education. With the nuns she traveled west but never known for her quiet temperament, she left the convent when she was still in her teens. Living by her wits and strength, she became known, as a hard drinker, a notorious brawler, a cigar smoker and one of the wildest women of her time.
The pistol-packing muscular, six-foot tall woman drew attention wherever she went and was constantly re-inventing herself as a successful entrepreneur. Over the years, she ran several restaurants in a number of towns in Montana,Wyoming, and southern Canada.