244 Explorer Set
General Information
The following information has been collected from original newspapers, catalogs, and magazines, some of which are freely available for reference below. The rest can be found in the site’s gallery. No aggregate catalogs (BrickLink, Brickset, etc.) were used.
Instructions: H-2309
Advertised Part Count(s): 244 pieces Set Box
First Year Confirmed Available: 1967(USA)
Sears exlusive from 1967-1971. USA Only.
Most Likely Retirement Date: 1971(USA)
It makes its final Sears catalog appearance in 1971. It also would not have been produced beyond the 1971 loss of the LEGO license.
Last Year Seen Available: 1972
The Berkeley Gazette, October 17th, 1972
Note: While this 1972 appearance of the 244 is not from Sears, the 244 was still a Sears exclusive from 1967-71 and the above example is likely getting rid of remaining stock.
Aliases:
49-4407,
244-Piece Set,
49-16096
Retail Price(s): $4.99(USA)
Discounted Example(s): $4.44(1967), $1.99(1972)
Rarity Score(Index): 3/7
Known Box/Packing Variants
There are two main variants of the 244 with sub variants in between. The first are the plain box versions of the set. These are very difficult to succinctly place in a neat timeline and there may be more, but they belong to 1967-69, known via their catalog numbers:


There are also several versions of the colorful box. It is the only Sears exclusive to have gotten a colorful box in 1967(known via this 1967 newspaper):
The box was updated to have eight patents sometime ~1968-69:

There may be a ~1969-70 version the new tabbed box, a single-piece gray tray, and eight patents. However, I have no corroborating example and its theorized existence is a result of following patterns left by other basic sets and not any informed source on this set specifically.
And then updated again in ~1970-71 to have eight patents, "Some parts...manufactured in Denmark" printed on the front, and tabbed ends:

To compare the two different styles(drawer/sleeve vs. the later tabbed ends), notice how the sides of the set changes overtime:


The above box is particularly enlightening as it supports the theory that at some point in or after the 1970 season, Sears no longer carried the plain box versions of most sets and instead used colorful boxes to fulfill catalog orders. Hence why a colorful box version of the 835 Advanced Builders Set released in ~1970-71.
Box/Overview
The 244 Explorer Set is a bit of an oddity for a number of reasons. Not only does it have all the variants seen above, but it also has a few very difficult to answer questions surrounding it.
Mainly, why is the 244 set the only Sears exclusive to carry a colorful box in 1967? The 536 Designer Set did not get such treatment until 1968-1969 and neither did the 835 Advanced Builder Set until ~1970-71.
It is only a simple reuse of the 205 Basic Set's box, which was common practice for exclusives(or inventory clearance sets) from 1962-1967. Even more odd, the below newspaper clipping confirms that some Sears were selling both the 205 and the 244 for the same price:

So while the frontier of LEGO Samsonite has shrunk considerably, there is still plenty to explore.
With that out of the way, let's look at the box(the same as the 205 Basic Set with a different set name/number):
The sides of the boxes were updated in 1970 when the box got tabs:

The tabs did as well:

Contents
In typical Samsonite fashion, the 244 Explorer Set's assortment probably changed throughout 1967-71. It was mostly just basic elements, though just note that while the box shows a green 10x20 plate, the 244 is typically only found with a grey plate.
The below example is an early mailer version:
