Wall/Asset history

Yellow	The block was introduced in this version.
Green	The block's texture was changed in this version.
Blue	The block's model was changed in this version.
Purple	The block's texture and model were both changed in this version.
Orange	Another visual change was made to the block in this version which does not fit in any of the above categories.
Red	The block was either removed in this version, no longer exists, or did not yet exist.
Cases where the model did not change are represented by cells spanning multiple rows. Cases where the model did change, but the change is not visible via the default view angle, are given separate cells. Changes which are not externally visible are not given cells.

From version		·	One direction				L-shaped				Straight		T-shaped				+	Textures used		Further info
From version		·	N	E	S	W	NE	ES	SW	NW	NS	EW	ESW	NSW	NEW	NES	+	Before	After	Further info
1.4.2	12w34a																	-		Introduction
1.9	15w31a																	-	-	The side walls are 1 pixel taller.
1.14	18w43a																			Texture Update
1.14	18w50a																			Texture Update
1.16	20w06a																	-	-	The block now has a "none", "low" and "tall" blockstate.

Blockstate Combination Table
1.16	20w06a	Height	One direction				L-shaped				Straight		T-shaped				+
		Height	N	E	S	W	NE	ES	SW	NW	NS	EW	ESW	NSW	NEW	NES	+
		Tall
		n
		e
		s
		w
		ne
		es
		sw
		nw
		ns
		ew
		esw
		nsw
		new
		nes

From version		·	One direction				L-shaped				Straight		T-shaped				+	Textures used		Further info
From version		·	N	E	S	W	NE	ES	SW	NW	NS	EW	ESW	NSW	NEW	NES	+	Before	After	Further info
1.4.2	12w34a																	-		Introduction
1.9	15w31a																	-	-	The side walls are 1 pixel taller.
1.14	18w43a																			Texture Update
1.14	18w50a																			Texture Update
1.16	20w06a																	-	-	The block now has a "none", "low" and "tall" blockstate.

Blockstate Combination Table
1.16	20w06a	Height	One direction				L-shaped				Straight		T-shaped				+
		Height	N	E	S	W	NE	ES	SW	NW	NS	EW	ESW	NSW	NEW	NES	+
		Tall
		n
		e
		s
		w
		ne
		es
		sw
		nw
		ns
		ew
		esw
		nsw
		new
		nes

Sources