When the first Europeans set foot on the North American continent, they clashed, both physically and culturally, with the native inhabitants. The Indian practice of taking, adopting, and sometimes torturing captives offended the Europeans more than any other practice. The treatment afforded to captives varied from tribe to tribe and tended to change as the Indians adapted to the new environment and adjusted to the increased pressure thrust upon them by the advancing whites. The primary sources used were Indian captivity narratives. The 111-volume "Garland Library of North American Indian Captivities" has made many of the better known narratives more readily available.