These photos are all marked "G. G. Bruckert, Harvard, Neb.". Gustave Bruckert lived in Harvard, Nebraska in 1900 and he was a photographer. By 1910, he had moved his family to Bruning, Nebraska and unfortunately died there in 1925. Bruning is 45 miles from Harvard, Nebraska.
The three people in these photos are much harder to research as there are no names or clues of any kind on the photographs. They likely lived in the Harvard area around 1900. They might have known my Negley family who lived near there at that time.