Helen Ellsworth Blair Chapman, letter writer from frontier Brownsville and Corpus Christi, the daughter of William and Emily (Welles) Blair, was born on April 4, 1817, in Westfield, Massachusetts, and educated at the Westfield Academy. She married 1st Lt. William Warren Chapman on August 29, 1838. As an army wife she lived in garrisons at various army posts including Fort Niagara, near Buffalo, New York (1838–41); Fort Columbus (Governors Island), New York (1841–47); Matamoros, Tamaulipas (January through mid-1848); and Fort Brown, Brazos Santiago, Point Isabel (mid-1848 through mid-1852), and Corpus Christi, Texas (mid-1852 until 1858). Her son was born in Fort Niagara, and her daughter was born at Fort Brown on October 23, 1851.
Helen Chapman was a literate and concerned citizen of the Texas frontier. Many of her letters to family, newspapers, and missionary organizations have been preserved, and they chronicle the early days of Brownsville and Corpus Christi, in many cases providing compelling portraits of the early citizens and events of the Rio Grande valley and the Corpus Christi area. Although the wife of the quartermaster at Fort Brown, Brazos Santiago, and Point Isabel, and consequently in a relatively secure situation, Mrs. Chapman witnessed and described the excitement and attractions of the frontier as well as its abuses. Notable were her observations on the lot of women and children in frontier society. Early during her Texas residence she initiated a letter campaign to friends in the East to bring charitable, religious, and educational influences to the Rio Grande valley and to Corpus Christi. By 1858, when the army transferred her husband to New York, she could point to many successes resulting from her letters. She had a high regard for the Mexican people and became an early advocate of equal civil rights for Mexican Americans when she realized that they were being denied the rights promised under the terms of annexation and the Treaty of Guadalupe Hidalgo, which ended the war with Mexico.
In 1851 Helen Chapman traveled to Mexico City and made many poignant observations concerning life in the Mexican capital. She resided in the North from 1858 until the end of the Civil War. William Chapman died in late 1859. He had engaged in many business ventures in both the Brownsville and Corpus Christi areas during his army tour there and had acquired substantial property in South Texas. Some of it was confiscated by the Confederate States of America during the Civil War and, in other instances, a few of her husband's former business associates denied their business relationship in an attempt to acquire her property. In her later years, she was involved in litigation to recover this property. After the Civil War she resided at various times in Corpus Christi and Columbia, South Carolina. Helen Chapman died on December 10, 1881, in Columbia, South Carolina.