When in the history of football (American) and basketball did the
criteria defining the illegal actions of intentional grounding and
traveling, respectively, become loosened?

I remember the days when both actions were routinely called and
penalized, but now both are as rare as hens' teeth. When did those
rules change and what prompted their change?

Hello,

In 1993, the NFL modified the intentional-grounding rule so that
quarterbacks could throw the ball away if they are outside the pocket.
As long as the QB is outside the tackles, and the ball gets to the
line of scrimmage, there is no penalty. Before 1993, any pass thrown
to avoid a sack was grounding if there was no eligible receiver in the
area. The league adopted the rule change to try to protect
quarterbacks from injury.

Source: Ray Glier, "Intentional Grounding Rule Modified," USA Today,
26 May 1993: 11C.

As for traveling, I've been doing exhaustive searches for an hour, and
I have not been able to find any evidence of a traveling rule change.
The NCAA hasn't had a major change to their traveling rule since 1921,
and the NBA's traveling rule isn't very different from that of the
NCAA, despite what you might reckon from watching college and pro
games. I suppose that officials have gradually allowed more leeway
over time, somewhat like the gradual de facto changes in baseball's
strike zone over the decades.

Source: NCAA, "Official 2003 Men's Basketball Records Book,"
http://64.233.183.104/search?q=cache:bq8oQVtlwYgJ:www.ncaa.org/library/records/m_basketball_records_book/2003/p237-244.pdf+ncaa+basketball+rule+changes+history&hl=en.

I hope this answer meets your needs. If not, please request clarification.

Search strategy:

history nba traveling rule
://www.google.fr/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2003-34,GGLD:en&q=history+nba+traveling+rule

nba traveling steps
://www.google.fr/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2003-34,GGLD:en&q=nba+traveling+steps

ncaa basketball rule changes history
://www.google.fr/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2003-34,GGLD:en&q=ncaa+basketball+rule+changes+history

nba rule history traveling
://www.google.fr/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2003-34,GGLD:en&q=nba+rule+history+traveling

site:www.nba.com nba rule changes history
://www.google.fr/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2003-34,GGLD:en&q=+site%3Awww%2Enba%2Ecom+nba+rule+changes+history

and many others...

Many thanks. I knew that the grounding rule had changed, just not when
or why. The "why" makes sense. As for traveling, today's big players
sail through the air farther than they'd gain over the floor if they
traveled!

If grounding means that the guys won't have shorts, I'm all for it.

Pink, I think you should send that recommendation to the NFL.