Using Max to return largest Epoch date for a column inside DateAdd function

I am trying to build a query that returns the "last date" associated with a specific user.  The "last date" is listed in the table as epoch time and I am attempting to convert the epoch time using DateAdd().  The statement below generates an Arithmetic overflow error when the statement is executed.
select top 1 (select dateadd(s, (select max(dbo.history.action_created_date)as action_created_date), 19700101) from dbo.history where dbo.history.ActionTakenBy like 'Nathan%') as MaxDate, dbo.history.act_name, dbo.history.ActionTakenDateText from dbo.history where dbo.history.ActionTakenBy like 'Nathan%';