According to criticism, "Carl Sandburg developed a unique and controversial form of free verse and simple style". The Fog is written in verse form, and although short, is a simple expression of an ordinary phenomenon in weather, fog.
The poem compares the approach of fog with the entrance of a cat into the room. When a cat walks into a room, it walks with such grace and presence. I have a cat and he moves with strides that always make his entrance into a room seem important.
Fog, like the cat's entrance, and departure is unpredictable. Often fog can simply dissipate without notice. It is ghost-like in its appearance, one can walk through it, see through it.
Fog puts a temporary veil on the horizon, it can be quite beautiful, especially when it rolls in low above the ground, almost like creeping, just like a cat creeps silently into a room.
Sandburg celebrates the simplicity of fog in this poem, an everyday occurrence, and draws us closer to nature and appreciating our environment.
And, noticing and appreciating the simple things in life, such as fog.