The early history of the Americas is filled with stories of heroic Catholic priests who recorded the customs of indigenous peoples, developed written forms of their languages, and often took up the struggle to defend native rights against the excesses of European conquerors.

Some of these stories are told in "The Cultures and History of the Americas," an exhibit at the Library of Congress that has just been extended until Sept 23. The show features 50 highlights from the 4,000 rare books, maps, documents, paintings, prints and artifacts of the Jay I. Kislak Collection recently donated to the Library of Congress

The collection focuses on the early Americas from the time of the indigenous peoples of Mexico, Central America and the Caribbean through the period of European contact, exploration and settlement. Since it broadens the focus of "American history" from just the Anglo-Saxon heritage, it will engage the growing Hispanic population of the United States as well as provide a basis for new scholarship.

The exhibit begins with a multimedia slide show, and includes a state-of-the-art interactive presentation of a rare printed book chronicling the depredations of Dutch and English buccaneers against the Spanish. By touching a screen, the visitor can leaf through every page of the book, pull out translations of the text, and zoom in on details of the engraved illustrations.

A visual feast, the display includes two of eight colorful large paintings of the Conquest of Mexico, created in 18th century colonial Mexico, an exquisite 3,000-year-old Olmec figurine and a set of colored maps of St. Augustine, Fla., in the Spanish era.

The history told by the exhibit is often sickening, of European theft of native lands, enslavement, ancient cultures wiped out — not to mention mutual massacres of Protestants and Catholics. And yet, many Catholic priests who went with the conquistadors left behind a more benign legacy, bringing the bloodless sacrifice of the Mass to people oppressed by human sacrifice.

The Aztec sacrifices were carried out on a genocidal scale, a fact that certainly helped Hernan Cortes pick up allies on his quick route to Tenochtitlan (later Mexico City). But human sacrifice was also practiced by the other pre-Columbian cultures.

One item in the Kislak collection is a set of illustrations, made in 1931 by the Mexican painter Diego Rivera, of the "Popul Vuh," an ancient text set down in hieroglyphic by indigenous writers in the 1550s, at the request of a Jesuit priest. This recounts the religious beliefs and legends of the ancient Quiché Maya, who inhabited the highlands of Guatemala. In one picture, one of the four gods given to the first humans instructs them to tear the hearts out of living persons in exchange for the gift of fire.

From an era when the glory of Mayan civilization was long gone, the exhibit has a priest’s handbook hand-written in at least two Mayan languages, Kekchi and Quiche, as well as Latin and Spanish. A remarkable survival, this book for everyday use is thought to have been created by Dominican fathers working with Indians in the mid-16th century in the Guatemalan highlands and contains lives of saints, religious instructions and hymns, guidance on marital arrangements and the Church feast days. One can only imagine the personal hardships that these priests endured in their love for the people they served.

From Florida comes the only known copy of a "Catechism in the Timucuan and Spanish Languages" written by Father Francisco Pareja and printed in Mexico City in 1627. This priest arrived in Florida in 1595, a decade before the first English settlement at Jamestown, and worked among the native peoples for 31 years. His writings preserve almost all that is known about the Timucuan language and customs. His catechism is the first printed religious book in what became the United States — predating the (Protestant) Eliot Bible in Algonquin by some 40 years.

The Kislak exhibit provides a balanced approach. The Museum of the American Indian on the Mall displays a wall of nearly 200 Bibles next to a wall of guns, implying two equal instruments of oppressing Native Americans. Yet, Kislak Collection curator Arthur Dunkelman points out the Bibles, which were the first written form of the Indian tongues, provide the unique basis for preserving these languages today.

A highlight of the Kislak holdings is a manuscript letter by Bartolomé de Las Casas to the Holy Roman Emperor Charles V. Las Casas first arrived in Santo Domingo in 1502 as a sailor on Columbus’s fourth voyage. He received a royal land grant including labor of the Indian inhabitants as a reward for his part in various expeditions.

He was shocked by the conquerors’ treatment of the Indians, and he returned to Spain in 1510 to become a Dominican priest, determined to devote his life to mission work in the Americas. In 1544 Las Casas was ordained Bishop of Chiapas, Mexico, where he worked to lighten the burdens of colonialism and became a fiery champion of indigenous rights. His letter to the king pleads for recognition of the fact that the Indians had souls (a view then debated in Spain) and must not be enslaved.