St. Patrick's Roman Catholic Church grew from a congregation founded in 1836 to serve Irish immigrants who came to the area to work on construction of the Wabash and Erie Canal from 1834 to 1837. Many of those Irish immigrants bought land and remained as permanent residents, using their religious and cultural interests to help build Lagro, originally platted in 1834, into a thriving trade center. The church dedicated its first building in 1838, and it was used for activities until it was razed in the 1960s. The present brick structure, built from 1870 to 1873 in the Victorian Gothic style, was made with brick from Huntington and Lagro and retains its original bell. Its features include hand-carved altars and statues, stained glass windows, and an oak and walnut curved stairway, and it was listed in the National Register of Historic Places in 1999.