Museums & Galleries serving Lehigh Valley. Rated 4.6/5 (43 reviews). From their website: The Moravian Historical Society (MHS) is home to some of America’s rarest treasures, illustrating the Moravian contributions to American industry, education, music, and art. Founded in 1857, MHS is the third oldest historical society in Pennsylvania. The historic site has two eighteenth-century buildings—the 1740-1743 Whitefield House and the 1740 Gray Cottage, the oldest extant Moravian structure in North America. The museum has over 20,000 historical objects important to the story of America.