Samuel C. Peoples was born on 8 April 1854 in West Fairfield, Westmoreland County, PA.Receiving a highly cross-trained education, Peoples earned his bachelor's degree from Wooster University (1878), a seminary degree from Western Theological Seminary (1881), and an M.D. from Washington and Jefferson Medical School.

On 28 June 1880, Peoples received his appointment to serve at the Laos Mission in northern Siam. He sailed for Siam on 18 September 1882 and arrived on 21 November 1882. During the trip, he met fellow Presbyterian missionary and teacher, Sarah Wirt. Sarah was born in Hartford, Ohio on 28 October 1851 and studied at Rockford, Illinois College. Their first assignment was in Chiang Mai, serving alongside esteemed northern Thailand missionaries, Jonathan Wilson and Daniel McGilvary. After a year of courtship, the two were married in the field in November 1883.

The Peoples showed an aptness and willingness to help expand the mission field. For over fifteen years, McGilvary and Wilson, and a few other missionaries had centered their focus on building up the Chiang Mai field. As the work expanded and Christians moved around, the need to station missionaries in new towns became more apparent. In 1885, the Peoples took on the responsibility for opening up a new station at Lampang (Lakawn). Dr. Peoples continued his medical work, and the two oversaw and taught at the boy's school. Unfortunately, the two had health issues while in Lampang and had to take furloughs to the USA in 1887 and 1889-90. However, this became fortuitous as Peoples, during his first health furlough, obtained the Lao type for the first press in Chiang Mai.

As Lampang Station became further established and with the senior missionary Jonathan Wilson taking residence there, the Peoples sought out yet again to assist in planting a new station. In 1894, the two traveled along with some faithful native workers, and their families traveled northwest to Nan Station. This move was their final, where they remained in service until 1920, with furloughs to the USA in 1905 and 1912-13.

Peoples was a fervent proponent in reaching out beyond Siam's formulating borders into French Laos, Shan State, Burma, and Yunnan, China. He would often send workers from his station to these fields to advance the gospel, a work that saw great fruit. Nan Church was one of the most vigorous missionary sending churches in northern Thailand. In 1897 and 1907, Peoples made trips to these areas and was all the more impressed with the need for more mission work in the SE Asia field.

History fondly remembers Dr. Peoples for helping to found the Nan Christian Hospital, Nan Christian school, and his modernization work alongside the Thai government in developing northern Thailand. Yet, the Peoples' primary efforts were to disciple the church's leadership and set it on a course of self-support.

Peoples was a fervent proponent in reaching evangelistic and bible training to elders and leaders in the church and then have them return to their homes and villages to advance the gospel.

After forty years of faithful service, Peoples died of tuberculosis on 27 December 1920. Sarah Wirt Peoples, his devoted wife, honorably retired on 17 April 1922 and died in the USA on 12 January 1932. Dr. Peoples Buried on a mountaintop which overlooks the town of Nan, Dr. Peoples gravesite has had a view of a city growing out of the jungle and become a strong bastion for Christianity in northern Thailand. Thanks to the foundations the Peoples family helped lay.