Russell taught that "this generation" referred to people in general, who were living at a significant time in history:
The Battle of Armageddon pp. 603-605
But understanding genea here, as elsewhere, to mean generation,
and recognizing that our Lord's words were a
prophecy covering the entire Gospel age, we have no difficulty
in understanding the statement to mean--"This generation
[which will witness the signs inquired for by the
apostles and just enumerated by our Lord--namely, the
darkening of the sun and moon and the falling of the
stars]--this generation shall not pass away until all these
things be fulfilled." In other words, the signs mentioned will
occur within a generation-epoch in the close of the age. [...]
A "generation" might be reckoned as equivalent to a century
(practically the present limit) or one hundred and
twenty years, Moses' lifetime and the Scripture limit. (Gen. 6:3)
Reckoning a hundred years from 1780, the date of the
first sign, the limit would reach to 1880; and, to our understanding,
every item predicted had begun to be fulfilled at
that date; the "harvest" or gathering time beginning October
1874; the organization of the Kingdom and the taking
by our Lord of his great power as the King in April 1878,
and the time of trouble or "day of wrath" which began October
1874, and will cease about 1915; and the sprouting
of the fig tree. Those who choose might without inconsistency
say that the century or generation might as properly
reckon from the last sign, the falling of the stars, as from the
first, the darkening of the sun and moon: and a century beginning
1833 would be still far from run out. Many are living
who witnessed the star-falling sign. Those who are
walking with us in the light of present truth are not looking
for things to come which are already here, but are waiting
for the consummation of matters already in progress. Or,
since the Master said, "When ye shall see all these things,"
and since "the sign of the Son of Man in heaven," and the
budding fig tree, and the gathering of "the elect" are
counted among the signs, it would not be inconsistent to
reckon the "generation" from 1878 to 1914--36 1/2 years--
about the average of human life today.
Rutherford altered this teaching in 1927 (Remember! "New Creation" = "Anointed"):
W 15. Feb. 1927, p. 62
Question: In Matthew 24:34 Jesus said: "Verily I
say unto you, This generation shall not pass, till all
these things be fulfilled." What did he mean by "this
generation" ?
Answer: It could hardly be said that he meant any
human being living on the earth at that time. He was
giving testimony concerning things that were to transspire
at the end of the world. That was a long way off.
No generation of the human race has ever existed as
long as a thousand years. It follows then that Jesus
must have meant something else. What could he have
meant ? At the Jordan Jehovah started a new generation,
a new creation, of which Christ Jesus is the Head.
Jesus selected twelve disciples, who were with him for
three and one-half years. Eleven of these we have
every reason to believe constitute a part of that new creation.
In 1 Peter 2:9 the apostle, speaking to the church
of course, referred to those who are faithful. The irresistible
conclusion therefore is that Jesus referred to
the new creation when he said: "This generation shall
not pass until all these things be fulfilled." This then
would be a strong indication that some members of the
new creation will be on the earth at the time of Armageddon.
After Rutherford's death, the teaching was again altered, "generation" no longer synonymous with "anointed" ("new creation"):
W 01. July 1942, p.204 par. 43
So too after the winter of Armageddon the remnant
and their companions will come forth from their
protected place under God’s hiding and enter into the
glorious season of the Kingdom in its undisputed
power over earth. (Job 37: 22-24) Pointing to the
events of our time since 1914 Jesus said : "Behold the
fig tree, and all the trees ; when they now shoot forth,
ye see and know of your own selves that summer is
now nigh at hand. So likewise ye, when ye see these
things come to pass, know ye that the kingdom of God
is nigh at hand. Verily I say unto you, This generation
[including the remnant] shall not pass away till
all be fulfilled." (Luke 21:29-32) (Brackets in original)
The teaching became more clearly defined in 1949 (and remained so until the major change in 1995):
W 15. July 1949, p. 215 par. 19
The generation of Jesus’ earthly days did not
thus see him arriving in Kingdom power. But that
generation was a prophetic illustration. It has its
modern counterpart in our generation from A.D. 1914
forward. This generation is the one that sees the Son
of man coming with the clouds of heaven as foretold
by Daniel, because in 1914, the year marking the end
of the Gentile times, Jehovah God gave the Kingdom
to him whose right it is.
(I hope someone will find this interesting!)