One of Texas' earliest and most generous benefactors was Rosanna Dyer Osterman. She was born February 26, 1809 in Germany, and married Joseph Osterman in Baltimore on February 23, 1825, at age 16. Her older brother, Major Leon Dyer, had escorted the captured Santa Anna to Washington late in 1836.

At Leon's urging, her Dutch-born husband traveled from Baltimore to Galveston to establish a business in the new Republic of Texas, and the next year, 1838, Rosanna traveled to the Gulf port to join him. In Galveston she helped her husband in his business, just as she had done in Baltimore.

When the Civil War broke out, military forces blockaded Galveston, and business came to a standstill. During battle, many Galvestonians evacuated to the mainland. Rosanna stayed to nurse the sick and wounded of both sides, After Galveston fell to Union forces, she acted as a courier of military information to Confederate officials in Houston. Her military intelligence helped the Confederates retake Galveston on New Years Day in 1863.

Three years later, Rosanna drowned after the explosion of a steamboat on the Mississippi River near Vicksburg. She was 57 years old.

In her will she left a fortune to medical facilities throughout the United States. She bequeathed several gifts of $3000 each. These went to Jewish hospitals in New York, New Orleans, and Cincinnati. Her funds formed the Hebrew Benevolent Society in Galveston that fed, clothes, and sheltered the impoverished, nursed the sick, and performed merciful deeds for the needy of all faiths. The gift was timely, because fifteen months later a yellow fever epidemic's large toll included forty members of the Jewish community.

Her bequest also left funds for the founding of a nondenominational Widow's and Orphan's Home in Galveston, funds to a Jewish Foster Home in Philadelphia (see the review of a biography of Rebecca Gratz, on this website), $5000 to build a brick synagogue in Galveston, $2500 to build a synagogue in Houston, $1000 to the first "Jewish Benevolent Society" in Houston, and funds to similar charities in New Orleans and Philadelphia. Her gifts also included $1000 to the Galveston Sailors Home.

At the time of her death in 1866, the Galveston News paid her this tribute: "The history of Rosanna Osterman is more eloquently written in the untold charities that have been dispensed by her liberal hands than by any eulogy man can bestow." It said her work made her distinguished for "unselfish devotion to the suffering and the sick."