The broth­ers Fred­er­ick and William Lan­gen­heim were of Ger­man ori­gin. In 1848 they were reg­is­tered with a pho­to­graph­ic stu­dio in Philadel­phia. They pro­duced daguerreo­types and had also acquired a licence to apply the calo­type process.
From 1854 onward, the Lan­gen­heim broth­ers began pro­duc­ing and dis­trib­ut­ing glass stere­oviews in the Unit­ed States. They col­lab­o­rat­ed with William Loyd and Alexan­der Beck­ers, who pro­duced the stere­o­scopes used to view Langenheim’s stereoviews.
From 1858 onward, the pro­duc­tion and dis­tri­b­u­tion of stere­oviews were con­sol­i­dat­ed under a new busi­ness named the Amer­i­can Stereo­scop­ic Company.
(from: Com­pendi­um of Stereoscopes)