
Did the Lord return in 1878 as predicted? The simple answer is NO
The date 1878 was a disappointment because no literal resurrection took place. In the end they concluded that it did take place but it was invisible.
1878: The Resurrection
1878: The Resurrection

The Finished Mystery (1917) p. 64:
“the awakening of the sleeping saints in the Spring of 1878.”
This date was also taught for over 50 years then changed to 1918:

the only object of that action was to mark a parallel point of time in this harvest, when he would in reality assume the kingly office, power, etc.; viz., in the spring of 1878, three and a half years after his second advent at the beginning of the harvest period, in the fall of 1874. The year 1878 being thus indicated as the date when the Lord began to take unto himself his great power, it is reasonable to conclude that there the setting up of his Kingdom began, the first step of which would be the deliverance of his body, the Church, among whom the sleeping members are to take precedence.
And since the resurrection of the Church must occur sometime during this “end” or “harvest” period (Rev. 11:18), we hold that it is a most reasonable inference, and one in perfect harmony with all the Lord’s plan, that in the spring of 1878 all the holy apostles and other “overcomers” of the Gospel age who slept in Jesus were raised spirit beings, like unto their Lord and Master. And while we, therefore, conclude that their resurrection is now an accomplished fact, and hence that they as well as the Lord are present in the earth, the fact that we do not see them is no obstacle to faith when we remember that, like their Lord, they are now spirit beings, and, like him, invisible to men. The facts that they are invisible, that tombs were not found opened and empty, and that none were seen...…
Thy Kingdom Come. Series 3 1908 Pg 234

They have shown us that since 1873 we have been living in the seventh millennium; that the lease of Gentile dominion, “The Times of the Gentiles,” will expire with the year 1914; and that the advent of him whose right it is to take the dominion was due in 1874. They have shown us that in the days of these Gentile kings, before their lease of power expires, the God of heaven will set up a Kingdom, and that the setting up of that Kingdom has actually been in progress since the year 1878; that there the resurrection of all the dead in Christ was due; and that therefore, since that date, not only is our Lord and Head invisibly present in the world, but all these holy messengers are also with him. And observe, further, that this date of the resurrection of the dead in Christ parallels the date of the resurrection of the Head of the body. Our Lord’s resurrection occurred three and a half years after his advent as the Messiah, in A.D. 29; and the resurrection of his body, the Church, we have seen, was due in the year 1878, three and a half years after his second advent, in October 1874. Prophecy has also indicated the manner of our Lord’s return, so that, though he is present, we should not expect to see either him or the risen saints, who are now in his likeness except by the eye of faith—faith in the “sure word of prophecy”; though we have learned that those who now constitute “the feet of Christ” shall also shortly be changed to the same glorious likeness. They shall then be spirit beings, like him, Christ, and like all the risen saints who are now with him, and will in due time see him as he is.
(1 John 3:2) We have also seen that the coming of the foretold Elias and of the predicted Man of Sin, which were to precede his advent, are accomplished facts. We have marked, too, the fixed dates to which the Prophet Daniel calls attention. The 2,300 days point to 1846 as… Thy Kingdom Come. Series 3 1908, Pg 305. Thy God Reigneth!
(1 John 3:2) We have also seen that the coming of the foretold Elias and of the predicted Man of Sin, which were to precede his advent, are accomplished facts. We have marked, too, the fixed dates to which the Prophet Daniel calls attention. The 2,300 days point to 1846 as… Thy Kingdom Come. Series 3 1908, Pg 305. Thy God Reigneth!
Studies in the Scriptures Vol. 2, 1906 p.218
1878 will be the end of the period of disfavor to fleshly Israel.
Jesus is present since 1874.
“But now we are in the end of this Gospel age, and the Kingdom is being established or set up. Our Lord, the appointed King, is now present, since October 1874, A.D., according to the testimony of the prophets, to those who have ears to hear; and the formal inauguration of his kingly office dates from April 1878 A.D.” (Studies in the Scriptures, Vol. 4, p. 621).
1878 will be the end of the period of disfavor to fleshly Israel.
Jesus is present since 1874.
“But now we are in the end of this Gospel age, and the Kingdom is being established or set up. Our Lord, the appointed King, is now present, since October 1874, A.D., according to the testimony of the prophets, to those who have ears to hear; and the formal inauguration of his kingly office dates from April 1878 A.D.” (Studies in the Scriptures, Vol. 4, p. 621).