SQL Server stored procedure that would enforce atomicity? Let's say I have following insert statements

INSERT INTO tEmpl  (lastName)  VALUES('Smith')
INSERT INTO tEmpl  (lastName) VALUES('Jones')
INSERT INTO tEmpl  (lastName) VALUES('Smitty')
INSERT INTO tEmpl  (lastName) VALUES('Smithson')
GO


What stored procedure would enforce atomicity? I mean, all inserts have to be executed at once or none of them. Please give examples. I am still learning SQL Server.
BEGIN TRY
BEGIN TRANSACTION

INSERT INTO tEmpl  (lastName)  VALUES('Smith'),('Jones'),('Smitty'),('Smithson') 

COMMIT TRANSACTION
PRINT 'Transaction committed successfully'

END TRY

BEGIN CATCH 
ROLLBACK
PRINT 'Transaction rolled back'

END CATCH