Aligning text in a table- right, left or center

I am trying to align the text in a table, but somehow the first cell with the year (1848) is not aligned. How can I fix this? Another question is: how can I specify if I want to align the text right, left, or centre in different columns . How can I also specify the size of the column width? r(2cm) Below is my WE:

 %---------------------Preamble---------------% \documentclass[twoside,b5paper,9.5pt,openright] \usepackage[total=,top=2.5cm,bottom=2.0cm,left=2.0cm,right=2.0cm, includefoot] \usepackage[english] \usepackage[T1] \usepackage[bitstream-charter] \usepackage \usepackage \usepackage \usepackage \usepackage[english] \usepackage % removes extra spacing between text \usepackage \pagenumbering % Remove page numbers in a section. The counting starts from Introduction \usepackage % fancy heading style in headers and footers \usepackage % use with savenotes to show footnotes % footnotemark can be used when you have to use the same footnote twice (to avoid repetition) \usepackage % include graphs/ figures in the file \usepackage % to set the line spacing in the document \usepackage \usepackage % to write pages in landscape environment \usepackage % to add footnotes to the tables \usepackage \usepackage % to create some space between table caption and table, otherwise there was no space \captionsetup[table] \usepackage[normalem] % to underline the text \providecommand\phantomsection<> \setcounter \usepackage \usepackage[labelfont=bf] \usepackage[font=] \let\newfloat\relax \usepackage \floatsetup[table] \floatsetup[figure] \usepackage \usepackage \usepackage \usepackage % to avoid printing the figure name (or otherwise, give figure names without spaces) \usepackage % figures as 6 (a), 6 (b) etc. \usepackage \usepackage \usepackage \raggedbottom \usepackage[compact] \usepackage[sort&compress] \usepackage \usepackage \setlength % spacing between different references \def\bibfont % fontsize of the references \usepackage[ singlelinecheck=false ] %---------------------Document starts here---------------% \begin % the document starts here! \begin[h!] \scriptsize \centering \caption)> \begin \toprule \textbf & \textbf & \textbf \tabularnewline \midrule 1878 & Bernard & Physiological state of cells can be maintained after the death of an organism \tabularnewline \rule 1885 & Roux & Maintained chick embryonic cells in warm salt solutions \tabularnewline \rule 1989 & Amgen Inc. & Recombinant erythropoietin produced in CHO cells \tabularnewline \bottomrule \end% \label% \end% \end