Part of the work that Joseph did was translating the Book of Mormon. Joseph said that an angel named Moroni visited him and showed him where a very old book was buried. This book was written on plates of gold (sometimes called the Gold Plates). It was buried in a stone box in a hill near Joseph's home in New York. Moroni visited Joseph once a year for four years until he told Joseph to take the Gold Plates. Since the book was written in a very old language, Joseph translated the book into English. He did this with help from God and by the tools called the "Urim" and "Thummim". The book was published as The Book of Mormon in 1830. It tells the story of two main groups of people who lived in North and South America hundreds of years ago (the Nephites and Lamanites), as well as a story of a group of people who came to the Americas thousands of years ago upon leaving the Tower of Babel (the Jaredites). It also teaches many things about Jesus. To members of The Church of Jesus Christ of Latter-day Saints, The Book of Mormon is a special book from God comparable to the Bible. Mormons believe that by reading The Book of Mormon and the Bible, people can learn how to get closer to God and how to find happiness in life. This book is also the reason Church members are sometimes called "Mormons".