April 15, 1947: A Great Day for Baseball (Magic Tree House) by Mary Pope Osborne

Jack sat on his front porch steps, his chin in his hand. It was the day for baseball tryouts.

"I've decided not to go," said Jack. "I can't stop thinking about last season's tryouts. I fell down when I swung the bat. Everybody laughed."

"Yeah, well, everybody laughed at me, too," said Annie. "Remember, I threw the ball to the wrong team."

"So maybe neither of us should go," said Jack.

"But our whole family loves baseball..." said Annie. Before she could finish, something dropped from the sky. A small white ball lay in the grass. "It's a baseball!" she said.

It doesn't take Jack and Annie but a moment to realize that they've been summoned for a mission by Morgan Le Fay, King Arthur's legendary librarian. The magic tree house was back.

Inside the tree house in the woods are two gray baseball caps and a fat book, The History of Baseball, with a bookmark for a page with a photo of Ebbets Field in Brooklyn, dated April 15, 1947, and a message from Morgan Le Fay

"'Twas a big day for baseball
So many years ago.
Journey to Ebbets Field
To learn what you should know."

The Morgan message tells the kids that when they put on the caps, they will be seen as two teenaged bat boys for the Brooklyn Dodgers, with instructions to "give the ball with the name to the one who knows the rules of the game." But why? What name? What rules? It's an intriguing mystery for this pair of intrepid time travelers.

When the magic tree house drops them in a grove of trees in a park, Jack and Annie find themselves wearing baggy Dodgers uniforms and long socks and ask two kids from the neighborhood, Olive and Otis, to show them the way to the game.

Jack and Annie, who has to be "Andy" for her job as batboy, race to the ballpark and get busy putting out the Dodgers' uniforms, gloves, bats, and balls, in the dugout. They can't help glancing at the crowd, women in dresses and white gloves, men in suits and hats. The stadium is packed and there's a nervous energy in the stands as the Dodgers and Braves warm up. Then they notice something really different from games back in Frog Creek.

Here, half the stands were filling up with mostly white people. The other half were filling up with mostly black people. Annie pointed to a black Dodgers player signing autographs on baseballs. "Who's he?" she asked.

And of course, it's April 15, 1947, the day of Jackie Robinson's first game as the first black major league player. Jack and "Andy" get to see Robinson fail to hit in two at bats and bear the jeers of the crowd with dignity and courage. Now they know what rules. And then they get to see him score the winning run in the game, and they know what name should be on that ball. Now all they have to do is discover the right person to receive that autographed game ball, in Mary Pope Osborne's latest in series, A Big Day for Baseball (Magic Tree House) (Random House, 2017). And for that they have to follow Otis and Olive home and meet his great, great grandmother.

It was a great day for baseball, and an important day in our history, and Annie and Jack, as well as their young readers, now know why they were there.

"You know... Morgan didn't send us to Brooklyn to become great baseball players," said Jack.

"I know," said Annie. "She sent us there to learn how to be brave and keep going. The rules of the game."

Author Mary Pope Osborne even appends some of the lingo and rules for playing the game of baseball, a sneak peak at the perfect book to pair with this beginning chapter novel in Osborne's best-selling series, its companion nonfiction book, Baseball: A Nonfiction Companion to Magic Tree House 29: A Big Day for Baseball (Magic Tree House (R) Fact Tracker).