The code below results in something other than the obverse and reverse being back to back, which is what I wanted. "turn" puts the center of rotation at the upper left corner of the image, but for this occasion one would need it at the center of the image. How is that done?
\documentclass[12pt]{article}
\usepackage{fancybox}
\usepackage{latexsym}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{fullpage}
\usepackage{rotating}
\begin{document}
\begin{center}
obverse: \doublebox{
$
\begin{array}{ccccc}
~1 & \quad & \text{THE UNITED STATES OF AMERICA} & \quad & 1~ \\
{} \\
& & \Huge{\bigcirc} \\ & & \text{george} \\
~1 & & \text{ONE}~\vphantom{\displaystyle\sum^1}~\text{DOLLAR} & & 1~
\end{array}
$
}
$${}$$
reverse: \doublebox{
$
\begin{array}{ccccc}
\text{\sc one} & & \text{THE UNITED STATES OF AMERICA} & & \text{\sc one} \\
& & \text{\sc in god we trust};\text{ all others pay cash.} \\ {} \\
& & \Huge{\bigcirc} \qquad \Huge{\mathbb{ONE}} \qquad \Huge{\bigcirc} \\ {} \\
\text{\sc one} & & \text{ONE DOLLAR} & & \text{\sc one}
\end{array}
$
}
\end{center}
\newpage
\begin{center}
\begin{turn}{-90}
\doublebox{
$
\begin{array}{ccccc}
~1 & \quad & \text{THE UNITED STATES OF AMERICA} & \quad & 1~ \\ {} \\
& & \Huge{\bigcirc} \\ & & \text{george} \\
~1 & & \text{ONE}~\vphantom{\displaystyle\sum^1}~\text{DOLLAR} & & 1~
\end{array}
$
} \end{turn}
\begin{turn}{+90}
\doublebox{
$
\begin{array}{ccccc}
\text{\sc one} & & \text{THE UNITED STATES OF AMERICA} & & \text{\sc one} \\
& & \text{\sc in god we trust};\text{ all others pay cash.} \\ {} \\
& & \Huge{\bigcirc} \qquad \Huge{\mathbb{ONE}} \qquad \Huge{\bigcirc} \\ {} \\
\text{\sc one} & & \text{ONE DOLLAR} & & \text{\sc one}
\end{array}
$
}
\end{turn}
\end{center}
\end{document}
