Journey to Galveston — Melodie A. Cuate

Book Seven in the award-winning series for middle readers, a sobering window on slavery in Texas
 
A struggle over a bowl of popcorn begins another time-traveling adventure for Nick, Jackie, and Hannah. When Mr. Barrington's trunk magically appears on the Taylors' kitchen table, a family of slaves steps out, followed by a snapping dog. Jackie is mistaken for an escaped slave and kidnapped by a hideous man. Trying to save her, Hannah and Nick are transported back to June 1865 only to discover that even though the Civil War has ended months before, many Texas plantation owners still own slaves.
            Befriended by twins Sam and Lily, the time travelers witness horrific truths of plantation life: whippings, beatings, and families being torn apart. After Lily is sold to another plantation in Galveston, they devise with Sam a plan to rescue her. Their race against time takes them through a spooky graveyard and over a river teeming with alligators, with vicious hounds in close pursuit.
            With the absorbing pace and historic detail that Mr. Barrington's Mysterious Trunk fans have come to expect, Cuate leads her protagonists, and her young readers, to the first Juneteenth.