Complex sentence: Just 4½ months after breaking ground, Maple Leaf Gardens was opened on November 12,1931, with many of the sold-out crowd of over 13,000 wearing evening clothes in response to Smythe's goals in building the arena.
Split into simpler sentences: Just 4½ months after breaking ground, Maple Leaf Gardens opened on November 12,1931. Many in the sold-out crowd of over 13,000 wore evening clothes in response to Smythe's stated goal in building the arena.