In 1910 when Sievers was commissioned to create the Virginia Monument at Gettysburg, Pennsylvania, he opened a studio in Richmond.
Following the success of the Virginia Monument at Gettysburg, Sievers sculpted a number of other statues commemorating the American Civil War, including the Confederate Monument in Woodlawn Cemetery, Elmira, New York, and others in Abingdon, Leesburg, Louisa, and Pulaski County, Virginia.
He further produced monuments to specific Confederate leaders, General Tilghman at Vicksburg, Mississippi and General Stonewall Jackson and Matthew Fontaine Maury, both on Monument Avenue in Richmond.
There are four portrait statues by Sievers in the Virginia Capitol, of United States Presidents James Madison and Zachary Taylor and two others, of Patrick Henry and Sam Houston.
Sievers is buried in Forest Lawn Cemetery (Richmond, Virginia).
There, a historical marker commemorating his workshop in the yard of a home on West 43rd Street stands in South Richmond.