In the 19th century, Manifest Destiny was a widely held belief in the United States that its settlers were destined to expand across North America. Historian Frederick Merk says this concept was born out of "a sense of mission to redeem the Old World by high example ... generated by the potentialities of a new earth for building a new heaven".In the 19th century, Manifest Destiny was a widely held belief in the United States that its settlers were destined to expand across North America. Historian Frederick Merk says this concept was born out of "a sense of mission to redeem the Old World by high example, generated by the potentialities of a new earth for building a new haven Hope that helped :)