From the valley or flat land
Bladen is likely a locational surname-turned-given-name, possibly derived from the Old English 'blaed' meaning a leaf or blade, or related to the village of Bladon in Oxfordshire. It is often associated with flat, open spaces or valleys. In the United States, it is also recognized as a county name in North Carolina.
Less common today
Bladen isn't in the latest US Top 1000. It last peaked at #2,033 in 2009.
US births per 5-year period, 1990βpresent (SSA data).