RE: Walls Don't Work: AKA A World Without Walls
I am looking through 1871. A lot of different things happened. I'll list a few. You can let us know which thing(s) you are referring to.
Jefferson Long of Georgia sworn in as 2nd black congressman Republican
1st Negro lodge of US Masons approved, New Jersey
US income tax repealed This is likely what you are talking about
Federal fish protection office authorized by US Congress
2nd Enforcement Act gives federal control of congressional elections in US
US Congress changes Indian tribes status from independent to dependent
US Congress establishes the civil service system
William Holden of North Carolina becomes 1st governor removed by impeachment
US 3rd Enforcement Act (President can suspend writ of habeas corpus)
Ku Klux Klan trials began in federal court in Oxford, Mississippi
Great Fire of Chicago kills 200 people and destroys over 4 square miles (10 square km) of buildings and the original Emancipation Proclamation
US President Grant (Republican) condemns Ku Klux Klan
Mob in Los Angeles, California hangs 18 Chinese
National Rifle Association is first chartered in the State of New York
Ku Klux Klan trials began in Federal District Court in South Carolina
The creation of a U.S. CORPS happened in 1871, it seems according to some people, the Act of 1871.