Merging two files horizontally and formatting - unix

Question

I have two files as follows:
File_1
Austin
Los Angeles
York
San Ramon
File_2
Texas
California
New York
California
I want to merge them horizontally as follows:
Austin Texas
Los Angeles California
York New York
San Ramon California
I am able to merge horizontally by using paste command, but the formatting is going haywire.
Austin Texas
Los Angeles California
York New York
San Ramon California
I realize that paste is working as it is supposed to, but can someone point me in the right direction to get the formatting right.
Thanks.

Answer 1

paste is using a tab when 'merging' the file, so maybe you have to post-process the file and remove the tab with spaces:
paste File_1 File_2 | awk 'BEGIN { FS = "\t" } ; {printf("%-20s%s\n",$1,$2) }'
result:
Austin Texas
Los Angeles California
York New York
San Ramon California

Answer 2

Firstly you have to check number of characters in the longest line. Than you may use fmt to pad line from the first file to greater length. Finish it using paste.

Answer 3

If you have an idea about the field width, you could do something like this:
IFS_BAK="$IFS"
IFS=$'\t'
paste file_1 file_2 \
| while read city state; do
printf "%-15s %-15s\n" "$city" "$state"
done
IFS="$IFS_BAK"
Or this shorter version:
paste file_1 file_2 | while IFS=$'\t' read city state; do
printf "%-15s %-15s\n" "$city" "$state"
done
Or use the column tool from bsdmainutils:
paste file_1 file_2 | column -s $'\t' -t