This document is from the papers of a family whose ancestors immigrated from Germany to the United States in the late 19th century:



> Zwilchenbart

> Basel  
> 9 Centralbahnplatz 9

> New York  
> 1 Broadway  
> gegenüber Castle Garden

> Aelteste bedeutendste General-Agentur für Auswanderung

> Amerikanische Bank

> Einzug von Erbschaften, Besorgung von Liquidationen  
> Geldwechsel

and then on the sides, in German and French:

> Diese Karte ist vor Austritt aus dem Castle Garden auf den Hut zu stecken.

> Prière de fixer cette carte sur le chapeau avant de sortir du Castle Garden.

Zwilchenbart is the name of a bank in Basel, about which the U.S. consul in Basel writes in 1900:

> It has been for very many years occupied with the transportation and with the financial arrangements of travelers, tourists, and emigrants.  
> <sub>([source](</sub>

This fits with the card's characterization of Zwilchenbart as "[The] oldest [and] most important general agency for emigration" (my translation).

However, I don't see anything that says what this card is for. The bilingual instruction on the side only puzzles me more:

> This card is [for one] to stick (pin?) on [one's] hat before leaving Castle Garden.  
> <sub>(my translation of the German)</sub>

[Castle Garden]( was New York's immigrant processing center from 1855 to 1890. The card indicates that Zwilchenbart has a bank branch opposite Castle Garden.

My best guess is that the card is a bank membership card, but if so, I'm puzzled that it seems entirely generic and doesn't bear any information about the account holder. **What is this card for, and why are immigrants instructed to attach it to their hat?**