The term "appropriation" can have several meanings. It can refer to the act of setting apart funds for a specific purpose. It can also refer to these funds that have been set apart. Finally, in terms of government, it can have two meanings. The first one refers to the act of "appropriating" something, or taking it as one's own. The second one refers to an authorization of money that is going to be used for a specific purpose. This is the meaning that best matches the way Hoover uses the word in this passage.
