author
A county office rather than a single named writer, this credit is attached to a detailed local history of Arlington County, Virginia. The work is best known for carefully tracing how the county’s boundaries changed over time and for turning public records into a readable historical reference.

by Va. County Manager Arlington Co.
Project Gutenberg and other catalog records list this author credit as "Va. County Manager Arlington Co." or "Arlington Co., Va. County Manager." In practice, that points to the Office of the County Manager, Arlington County, rather than to an identifiable individual author.
The office is credited with A History of the Boundaries of Arlington County, Virginia, a public-history work that draws on official records to document the county’s changing borders and legal development. The book has been described in library and ebook listings as a historical reference work, and its institutional authorship fits that documentary style.
Because the credit refers to a government office instead of a specific person, there does not appear to be a single personal biography or official author portrait to include. For audiobook and library readers, it makes most sense to think of this author entry as an institutional byline for Arlington County’s historical research and recordkeeping.