Lists are not displaying full width in 1 column layout boxes

I'm not sure what is wrong here, but I am having trouble creating  a full width view of a custom list inside of a single column sharepoint site page.  Here are my steps...

• From my share point site, I created a new page
• I then added an app -> Announcements -> customized it with 3 columns (Tags | Title | Body)
• I then went back to my SharePoint page, clicked Edit
• I added a new section
• Selected One Column
• Added a List
• Selected my Announcement List
• Clicked Republished

and this is the result I see on my browser Window...

Why does the body column get dramatically cut off (yet the header link for All Items is all the way to the right)?  How can I see the full extension of my list along the x-axis of my screen?

Here is another look at the same list being dramatically cut off...