Speedway Express in Lancaster County, PA, could be considered the source of the original Little Red Wagons.  They have been making very popular classic wood wagons since 1962. Words from the founder:

"We hand make our woodcraft wagon bodies from the finest hardwood. The red racks are stapled & glued to assure a stronger bond.
Each wagon is built in our shop to conform to strict specifications, from no tilt auto turn steering and ball bearing wheels to welded heavy gauge steel framework to handle heavy loads.
They are suitable for pleasure riding as well as gardeners, farmers or contractors. Sturdy, well-built and long lasting ... Our Speedway Express Wagons will give you and your family years of enjoyment."

Features we love about Speedway Express:

• Our most established Amish wagon maker, with a history of excellence
• 
  Pneumatic tires, available for most models, that roll smoothly and quietly while carrying heavy loads
• Painted or varnished woodwork and steel frames for a durable wagon that can withstand the elements longer
• Multiple bed sizes available from small to the largest we carry.  (Inside bed dimensions are -2.5" width and -3.25" length less than the official dimensions listed.)
• An adult-length handle with a comfortable "D" shape on larger wagons 
• A remarkable variety of colors, accessories and trailers, which can be viewed under the accessories category