\documentclass[10pt]{book}
\usepackage[letterpaper, margin=1in]{geometry}
\usepackage{multicol}

\title{Wilderlands of High Fantasy \\ Players' Guide}
\date{for ACKS (and other OSR systems)}

\begin{document}
\frontmatter
\maketitle
\newpage

\mainmatter

\chapter{History of the Wilderlands}

This chapter details the history and calendar of
the Wilderlands.

\include{zCalendar}

\include{zHistory}

\end{document}

