While the numbers show that $5000 inflation-adjusted is more achievable now than in the past, I suspect most of that progress was made in the 25 years immediately following then. Also, the numbers are per household, and a lot more households have multiple wage earners now.
The first link says the median salary was $3000 not $36000. So $5000 would represent 166.7% of that salary.
You are in fact correct, I put my misreading down to too much Christmas spirit.
While the numbers show that $5000 inflation-adjusted is more achievable now than in the past, I suspect most of that progress was made in the 25 years immediately following then. Also, the numbers are per household, and a lot more households have multiple wage earners now.