Also R.B.C. Howell was not as simple of a figure as many non-Landmarkers want him to be. Like many modern church splits, the division between Graves and Howell was due to strong personalities as much as anything.
Consider the following quotes from Howell:
"I assert that the Baptist church has existed, in a state of comparative purity, connected with neither Papists nor Protestants, in every period since Christ, and that in this sense God has not left Himself without witness."
"Is the immersion in water, of a believer, by a properly authorized minister, in the name of the Father, and of the Son, and of the Holy Ghost, the only baptism? All Baptists reply in the affirmative. Then Pedo-baptists are not baptized. To commune with them, therefore, is to violate the law of Christ".
Both quotes sound like they are from J.R. Graves, but both are actually from R.B.C. Howell. The two agreed on far more than most realize.
Also Howell wrote some bitter and nasty things about Graves, Dayton and Pendleton. Most people who talk about Howell and the division at FBC Nashville have never studied the issue deeply or read the original writings of the time.
I was at work when I responded the first time and was not at my computer (my memory is not the best so I keep notes and references on my "other brain"

).
Graves illustrated the relationship of “true churches” throughout history as being in accord with the relationship between any regular Masonic Lodge and the first Lodge that was instituted. Within Freemasonry, lodges exist and pass away, but this does not affect the continuity of Masonry. Likewise, individual churches exist and pass away, but this does not affect the continuity of the Kingdom of Christ in the visible church (Graves,
Old Landmarkism: What is it?, 122)
Howell seems to hold a similar position. But there are differences.
“The scriptures speak of the kingdom of Christ upon earth, and the churches of Christ upon earth. These however are by no means identical and must not be confounded together. The kingdom of Christ upon earth is purely spiritual. It is consequently invisible. All these persons are subjects of this kingdom in whose hearts Christ reigns as supreme Ruler and Lord. Everyone who is regenerated by the Spirit of God is legitimately and truly a member of the invisible kingdom of Christ. All persons will be saved whether baptized or not, or whether in or out of a visible church.” What Howell viewed as the most fatal error of the Landmark argument was an assumption of “the existence of a universal visible church upon the earth, with an actual government, officers, and ordinances” (Howell,
A Memorial of the First Baptist Church, 156-157).
In a letter to the Mississippi Baptist State Convention Howell addressed Landmarkism as “heterodox in principle” and “incapable of any practical application” (Howell addressed a series of letters for publication in the Baptist Standard, but they were never published due to the suspension of the paper. They are housed at the Baptist Historical Library and Archives in Nashville).
Howell believed that the visible church is a “congregation of believing men and women, organized for the worship of God and the assembling for that end in one place”; that regeneration initiates the believer into the kingdom of God, this “invisible kingdom”, while baptism initiates into the visible church; “visible churches on earth are the multitudes of congregations scattered everywhere, each one of which is a distinct church, and responsible to no other, but only to Christ its head” (Howell,
The Terms of Communion at the Lord’s Table, 248-250).