Commented Unassigned: Receiving error: "Install-Package AjaxControlToolkit.StaticResources..." [27787]

I am using Visual Studio 2013 Community.

I installed the AjaxControlToolkit v15.1 using the downloadable installer.

I created a new Web Forms Project running on .net 4.5

I successfully ran the following commands in the NuGet prompt:

* Install-Package Microsoft.AspNet.Web.Optimization
* Install-Package AjaxControlToolkit.StaticResources

I added the following to my ScriptManager:
```
<asp:ScriptReference Path="~/Scripts/AjaxControlToolkit/Bundle" />
```

I added the following to my head tag:
```
<asp:PlaceHolder runat="server">
<%:System.Web.Optimization.Styles.Render("~/Content/AjaxControlToolkit/Styles/Bundle") %>
</asp:PlaceHolder>
```

When I run my project this is the error I receive in my browser:

Could not load file or assembly 'AjaxControlToolkit, Version=15.1.1.100, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' or one of its dependencies. The system cannot find the file specified.
...

What am I doing wrong??
Comments: My project already has a reference to 'AjaxControlToolkit.StaticResources'. Is there another reference I need to add? If so, where is it located??