Compass South by Hope Larson
This graphic novel starts in New York City in 1860, where twins Cleopatra and Alexander Dodge join up with the Black Hook Gang after their father disappears. After Alex gets caught stealing, Cleo disguises herself as a boy and the twins run away to California. On the way over, they meet new friends (and foes) and get separated, pursued by gangsters and pirates. With one twin stowed away on a boat and the other pressed into service as a cabin boy on a ship, it's a race against the clock for the twins to find one another again, and maybe locate some pirate treasure before the villains!
This is the first book in a series, and I can't wait for the next one to come out! It's full of adventure, swashbuckling, sword fighting, and friendship, not to mention pirates and secret treasure. This was very fun and exciting, and I really liked Alex and Cleo. They were clever in different ways, and I was definitely rooting for them. Go read this if you like adventure stories or the Pirates of the Caribbean movies!