Compiling data from different worksheets.

Sub Copy_SheetsTwo_To_Last()
Application.ScreenUpdating = False
Dim i As Long
Dim Lastrow As Long
Dim Lastrowa As Long
Lastrow = Cells(Rows.Count, "A").End(xlUp).Row + 1
    For i = 2 To Sheets.Count
        Lastrowa = Sheets(i).Cells(Rows.Count, "A").End(xlUp).Row
        Lastrow = Sheets("Master").Cells(Rows.Count, "A").End(xlUp).Row + 1
        Sheets(i).Range("A2:Z" & Lastrowa).Copy Destination:=Sheets("Master").Range("A" & Lastrow)
    Next
Application.ScreenUpdating = True
End Sub

' this is your sub procedure
' you can either directly run a sub procedure
' from within the VBA editor (ALT + F11)
' or you can assign it to a button (there are other ways as well).
Sub Copy_SheetsTwo_To_Last()


    ' disabling screen updating will speed up your macro code.
    ' it tells excel not to update your screen with with information
    ' every time it makes a calculation. even though you cant see
    ' your macro being executed, it does, and faster.
    Application.ScreenUpdating = False


    ' delcare our variable types
    Dim i As Long
    Dim Lastrow As Long
    Dim Lastrowa As Long


    ' this will return the last row of our active worksheet
        ' Worksheet.Cells Property:    https://msdn.microsoft.com/en-us/library/office/ff194567.aspx
        '           Count Function:    https://msdn.microsoft.com/en-us/library/office/ff193349.aspx
    Lastrow = Cells(Rows.Count, "A").End(xlUp).Row + 1
    
    ' for each sheet (Sheets.Count),
    ' starting with sheet 2 (so as to skip the master sheet)
    For i = 2 To Sheets.Count


        ' return the last row of the selected worksheet (Sheets(i))
        ' where i is equal to the worksheet number.
        Lastrowa = Sheets(i).Cells(Rows.Count, "A").End(xlUp).Row


        ' return the last row of the "Master" worksheet
        Lastrow = Sheets("Master").Cells(Rows.Count, "A").End(xlUp).Row + 1


        ' for each worksheet, other then master, copy the range from cell A2,
        ' to the last row in Z; then copy that data beginning at the last
        ' used row of "Master" worksheet
        Sheets(i).Range("A2:Z" & Lastrowa).Copy Destination:=Sheets("Master").Range("A" & Lastrow)
    Next


    ' make sure we enable screen updating again
    ' before we end our macro so as to restore expected
    ' behavior while using excel.
    Application.ScreenUpdating = True


End Sub