A blank map of United States counties.  Every county's object in this SVG has its  FIPS code in the object id field, with the county name and 2-letter postal state abbreviation in the title field.  In cases where there is a county in a state that also has a county-equivalent city of the same name, "Co." is appended to the county name.  In all other cases, "County", "Parish", "Borough", or other county equivalent is omitted from the name. This file includes the FIPS codes changes and county name updates to Kusilvak, AK (FIPS - 02158) &amp; Oglala Lakota, SD (FIPS - 46102) as of 2015 per census.gov: https://www.census.gov/geo/reference/county-changes.html
Examples of id and fields:

Mercer Co., New Jersey

id="34021"
title="Mercer, NJ"St. Louis, Missouri
This is a city and county:
id="29510"
title="St._Louis, MO"St. Louis Co., Missouri
This is an adjacent county separate from the city of St. Louis:
id="29089"
title="St. Louis County, MO".
In this file, the id is meant for machine processing, and the title is meant for human consumption.  As SVG files are easily parseable and readable text files, it is fairly simple to write a program or script that creates a copy of this map with the color of certain counties based on some datum, such as population density, e.g.  Much such data includes FIPS codes, which provides an easy and fool-proof way to identify the associated SVG object in the map.
File:USA Counties with names.svg
File:USA Counties with names.svg: User:Mr. Matté
derivative work Kbh3rd
derivative work: Fredx100