These three carte de visites or CDVs were made in the mid to late 1800s as evidenced by the photographers' histories and by the clothing the children are wearing. I am estimating that the first and third photos are older and were made in the mid-1800s. I believe the second photo to be a tad bit later, again based on the clothing.
The first and second photos are of young girls and the third photo is of a young boy. Girls usually wore their hair parted in the middle and boys usually had side parts. Even in photographs where it looks as if the subject is a young girl, a side part is pretty much confirmation that one is viewing a young boy.
Also of interest may be the posing stands apparent in the last two photographs. The posting stand is of heavy metal with a brace of sorts at the top to hold the subject's head in place so they wouldn't move, which would cause a blurry photograph.
Here is a photo (https://www.icp.org/browse/archive/objects/photographer) of Benjamin Lochman, one of the photographers. William H.S. Gross appears in Reilly's PA Business Directory for 1868-1869 as a photographer in Allentown, PA. Thank you to http://www.langdonroad.com/gl-to-gy for the information on Gross and to the same site at http://www.langdonroad.com/lo-to-ly for the information on Lochman.
The first photo is 4" x 2 7/16". The second photo is 4 ⅛" x 2 ½". The third photo is 4" x 2 7/16".
Each CDV has the photographer's name/imprint on the back.
Please note wear, especially at corners of each of these photos.
The price is for all three CDVs.
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