Get the latest date

I have an array that I call $data.

I want to get the earliest dates from the $data array for each host in my csv file. The user will input a host and it will find the earliest date it was modified.

    Hostname    LastModified
    HD           9/8/2012
    LOG          9/15/2004
    NETMAN       12/25/2004
    NETMAN       5/5/2015
    LOG          1/4/2013
    LOG          6/6/2011

So if they input LOG, I want it to give me the earliest date.

    Created on  9/15/2004

Code:

 $data= import-csv ".\Earliest Date Template.csv" 
 $Hostname=Read-Host "Please enter Host Name"
 $data | Foreach-Object {$_."Last Modified" = [DateTime]$_."Last Modified"; $_} | Group-Object Hostname| Foreach-Object {$_.Group | Sort-Object LastModified | Select-Object -First 1}