El ferrocarril transcontinental (The Transcontinental Railroad)

People today refer to the Midwestern and prairie states as flyover country. During the Civil War, crossing those areas was the biggest obstacle in uniting the East and West Coasts of our divided nation. An act of Congress in 1862 authorized the Central Pacific and the Union Pacific railroad companies to build a railroad that would link the coasts. Seven years later, on May 10, 1869, an overwhelmingly immigrant labor force completed the task when a rail line was join in Promontory, Utah. The states had become united at last.

Mysterious ancient ruins, hidden deep in the jungle of southern Mexico In May 1840, explorers John Stephens and Frederick Catherwood road their mules along a steep, muddy jungle path. They were hoping to find the ruins of an ancient, deserted site in Mexico they knew only from visitors’ accounts. Through the trees, they spied the remains of a crumbling stone palace. Palenque! In the weeks they spent there, the men discovered intricately designed buildings and mysterious glyphs, or symbols. Who built this city? What did the glyphs mean? The questions remained largely unanswered until the...

Introduces the life and times of Underground Railroad and anti-slavery leader Harriet Tubman and explains her place in American history.

El mundo natural es un lugar extraño donde ocurren las cosas más insólitas y sorprendentes. Récords, curiosidades y extravagancias reunidas por temas: botánica, animales salvajes, domésticos, acuáticos, reptiles, insectos, aves, dinosaurios y fenómenos naturales, para enterarse de que el sauce enano no pasa de los 6 cm de altura, que los dientes del hipopótamo pueden llegar a medir medio metro, que el camello puede beber hasta 150 litros de agua de una sola vez, que el cocodrilo puede aguantar la respiración bajo el agua una hora... ¡lee y descubre!

Have you ever wondered what Space Camp is like? Join Isabella as she moon walks through the Moon Room, takes a ride in a Multi-Axis Trainer, tackles the Mars Climbing Wall, and takes the helm at Mission Control. Along the way, you'll practice measuring time. This fiction math book seamlessly integrates the teaching of math and reading, and uses real-world examples to teach math concepts. Text features include images, a glossary, an index, captions, and a table of contents to build students' vocabulary and reading comprehension skills as they interact with the text. The rigorous practice...