I am going to give my suggestions for two other ways it could have slipped in. Firstly during the early 18th Century, when a high level of rationalism got into Non-Conformity. The split in one of the baptist groupings and in English presbyterianism which resulted in the formation of Unitarianism happened at this time with people feeling that Trinitarianism was irrational. Unitarians where they have eucharist are pretty strict memorialists.
If you then add the fact that the Evangelical Revival was nowhere like as simple as a setting up of the Methodist Church but also led to a revival in established Dissenting congregations, you have the seeds corn for this view of eucharist going into the main stream evangelicalism.
However the heyday of Evangelicalism is in fact the Victorian Era, and this was also the time when Non-conformists saw themselves as the "New Establishment" setting up Schools, Universities and Hospitals. The missionary movement was at its height and the tendency of Victorian to pride themselves on being rational, could at least lead to again an increase in those taking the stance of memorialism. This was an age that felt it could do away with superstition.
Now Memorialism's attractive point is that it does not require any belief in power outside that of the human mind for its effectiveness. No hidden spiritual stuff.
If you then add the fact that the Evangelical Revival was nowhere like as simple as a setting up of the Methodist Church but also led to a revival in established Dissenting congregations, you have the seeds corn for this view of eucharist going into the main stream evangelicalism.
However the heyday of Evangelicalism is in fact the Victorian Era, and this was also the time when Non-conformists saw themselves as the "New Establishment" setting up Schools, Universities and Hospitals. The missionary movement was at its height and the tendency of Victorian to pride themselves on being rational, could at least lead to again an increase in those taking the stance of memorialism. This was an age that felt it could do away with superstition.
Now Memorialism's attractive point is that it does not require any belief in power outside that of the human mind for its effectiveness. No hidden spiritual stuff.