Final answer:
Annie Moore, a young girl from Ireland, was the first immigrant to go through Ellis Island on January 1, 1892.
Step-by-step explanation:
The first immigrant to arrive at Ellis Island was Annie Moore, a 15-year-old girl from County Cork, Ireland. She arrived on January 1, 1892, and was greeted with a celebration for being the first person to be processed at the newly opened immigration station. Ellis Island served as a gateway for millions of immigrants to the United States and holds a historic place in America's development.